Understanding Laser Power and Energy Measurement Technologies

Transcription

1 Understanding Laser Power and Energy Measurement Technologies Foreword Laser Point manufactures a complete range of state-of-the-art detector heads and monitors for measurement of powers and energies of all lasers, from UV to the Far Infrared, in any application within the industrial, medical or scientific fields. Those detectors can mate to a whole family of precise and sophisticated monitors and meters which include intelligent detector connection, analog and digital displays, analog and digital outputs and application software. Technology Laser Point has put a lot of technology into the design of its heads. A head is substantially made of a sensor disk and a housing with its heat sink or cooling devices. Each of these assemblies are critical in view of the final performance of the system. Parameters like thermal stability, linearity, spatial uniformity, heat dissipation are calculated by our Engineers and extensive thermal SW modelling (Thermal Analysis System-TAS) is made to verify the behaviour and achieve the highest reliability even in those demanding environments represented by high power lasers. Absorbing coatings are another important chapter in the head design. They have to face high damage thresholds as a function of the wavelength of use. LaserPoint has adopted various types of radiation absorbers, simulated by TAS and deposited with the latest technologies (e.g. plasma) under the tightest specifications, to resist extreme thermal and mechanical stresses. 10W-Sensor Disk 5KW-Cronos Selecting a measurement system The selection of a measurement set-up is, in general, an easy task. On the following pages you will find detailed specifications for each of Laser Point s heads and readout units that will help you in defining what is needed for your application. Of course there may be exceptions or special requirements: in those cases feel free to apply to our Engineers or Distributors for complete technical support. The first step in the selection is to look for a detector capable to match the power and/or energy specifications of the laser; the next is to select a monitor that meets with user s requirements, e.g. having a graphical display or an application SW. The entire working range has to be determined. The Power or Energy Resolution represent the minimum values which can be detected with an optimum signal-to-noise ratio, while the Max Continuous Power or the Max Energy are the maximum values at which the detector can safely work with no time limits. Nevertheless, should there be the necessity to make measurements at higher powers or energies, this can be done for a limited period of time, up to 1.5 times the max value (Intermittent Power Use). Verify if Absorber Type, Wavelength Range and Max Average Power/ Energy Density specs are consistent with the laser type; furthermore when working with short pulses (as is the case of various medical lasers or Q-switched Nd-Yags) and want to measure average power, attention has to be given to the Max. Peak Power Density. LaserPoint has a wide selection of products whose absorbers, like those working on the volume absorption principle, offer the highest damage resistance to short pulses. The Cooling type is another feature to look at; if bringing water to the head is a problem, there are convection or fan cooled detectors which can be used. For example, our A-600 head can work at 600W continuously or dissipate 800W for a short period, but that s really a technological goal of LaserPoint thermal design. For higher powers water cooling is necessary. Finally, LaserPoint s versatile and best-buy monitor PLUS or industry favorite LPM are the user friendly meters to be associated with any of LaserPoint detectors.

2 Operating Principles of Thermal Heads This section describes the very basics on which LaserPoint s sensors and detectors work.it is intended to introduce the laser user with terminology and principles which are repeatedly mentioned in the catalog and can be used as a help in choosing the power/ energy instrumentation. Thermal methods of measuring power and energy are those in which radiant energy is absorbed and converted into heat, thus creating a temperature rise in the absorber. The absorbed energy can then be measured by monitoring a temperature gradient between the hot area ( where the laser strikes) and a cool area (where the generated heat is dissipated). This measurement can be done by means of thermocouples arrays (thermopile). The temperature difference will generate a voltage at the end of each single thermocouple, so if the array is duly distributed, the resulting total voltage will be proportional to the incident power or energy. As the generated voltage depends on the temperature difference between the hot and the cold areas it results that there is no influence of ambient temperature on the measurement. Thermal detectors exhibit an intrinsic high degree of linear response at the increase of power levels (linearity); a compensation for the minor drops in linearity occurring at the working temperature extremes are made with the use of thermistors. Linearity of LaserPoint s detectors, thanks to their optimised thermal design, is excellent: as an example, for the W-0 head as measured by PTB (Physikalisch-Technische Bundesanstalt) in the range between 60-0W, it remains within +/-1 % without compensation. The generated heat all flows through the thermocouples, whether they deposited on circles (radial thermopiles) or linearly, with the hot and cold areas facing each other (axial thermopiles). Since the total signal is given by the sum of contributions from all thermocouples, the result is the independence from laser beam size and position The response time is determined the thermal resistances, the thermal capacities and, mostly, by the geometrical sizes of the sensor disks. The intrinsic response times of detectors is significantly reduced by appropriate acceleration algorithms in LaserPoint s monitors. A detector like LaserPoint s A-300, which has an intrinsic response time of 11 sec due to its very large area, displays the final power value only after 3.5 sec. To dissipate the generated heat a thermal sensor must be placed within a housing which, depending on the amount of heat to be driven away, can work by simple convection, have electrical low voltage fans or be water cooled. So as the thermal contact between sensor and housing is very critical since it might generate overheating of the sensor and instabilities in the signals, the final shape and dimensions of the heads must be carefully designed to maintain the sensor temperature within its working limits. An example of excellent thermal dimensioning is LaserPoint s W-6000 head, which can safely work up to 9KW.

3 A New Approach on Thermal Heads Design: the FIT Product Lines In some sections within this catalog Fit detectors are mentioned. These heads are available for different applications : as laserprobes, where a full product line bears the same Fit name and as detector heads for the PLUS monitor or the Laser Process Monitor LPM. Fit, acronym for Fast Integrative Thermopile, is a measurement technique of temperature dynamics throughout thermopile sensors developed by LaserPoint (Patented.) which led to a novel family of detectors. A dedicated algorithm converts sensors data into fast, repeatable and precise readings. Fit detectors have provided a series of breakthroughs in laser measurement: infact, while keeping the advantages of thermopile detector heads (e.g. their use at any wavelength or their fast response times), Fits need no water cooling even when working at several kilowatts, while still allow repeated measurements. As a laserprobe, no other similar instrument on the market has ever been so repeatable and precise, before. Fit detectors can be used in all those cases where availability of cooling water is an issue or when space is limited but,above all, where long term laser power measurements are not necessary while quick, occasional checks are enough. In these cases the Fit detectors, either associated with a Plus monitor, an LPM or working as a standalone laserprobe, provide performance comparable to power meter measurements, at a real fraction of their cost. FIT-6000-H (6KW )- No Water Cooling Radiation Absorbers LaserPoint detectors can measure over the complete range of wavelengths interested by lasers, up to many kilowatts of power and hundreds of Joules of energy. It is thus evident that there is a necessity to use many kinds of different absorbers to accommodate so many situations. A-Surface Absorbers- Surface absorbers consist in materials deposited onto substrates that can easily transfer heat, like copper or aluminium. They are used for CW lasers or other sources that emit long pulses (with duration >300µsec). Radiation is almost entirely absorbed within a thin layer by materials like special mattes or refractory materials and then released as heat which flows through the thermopile. Broadband Coatings: for low powers and general purpose applications LaserPoint utilizes a black coating (BBF) derived from astronomical research. The power density capability is limited to 200W/cm 2, but has the important advantages of a flat spectral response in the range µm and the bearing of a very high absorptivity (> 96%) over the entire range. A general purpose hard coating (HCB) for more demanding applications is used by LaserPoint for mid power lasers. It can be used over a broad spectral band ( µm) and some sensors ( as the W-200) bear specially shaped surfaces that reach a 97% absorptivity by dumping the radiation with multiple bounces. This coating reaches 2500W/cm 2 at full power with 300W CW operation. At pulsed operations it can withstand up to 300J with long (msec) pulses. High Power Coatings: standard broadband absorbers can hardly withstand the disruptive situations generated by high power industrial lasers. LaserPoint has developed new high density and better thermal conductivity coatings for those demanding lasers. On LaserPoint heads from 1KW to 3KW the HPB absorbers can withstand 4KW/cm 2 for CO2 in CW operations. LaserPoint s HPI coating was developed for even more stringent situations and is applied on the 6KW head; it withstands 5KW/cm 2 at 10.6µm and works in the range µm-10.6µm. Excimer Coatings: LaserPoint has developed a very hard absorber with flat response in the range µm, ideal for its use with industrial Excimer lasers. It has also a remarkable high absorptivity at 10.6µm, so it may as well be used for CO2 lasers. The ridged substrate surface induces multiple reflections that increase absorption to the highest available levels on the market. In the UV the coating can withstand >0.3J/ cm 2, high repetition rate, nsec pulses at 248nm and has a peak power density capability >20KW/cm 2. Coating Damages. The damage threshold is defined as the level at which readings will change more than 1%. When exceeding this value the absorber surfaces will visibly change colour and the head calibration has to be reconsidered if the damaged area is important compared to the overall. In some cases a complete substitution of the sensor may be necessary. Yet, as very often happens, there may be a bleach on the coating but no at all, or just negligible change in the readings: those colour changes are barely aesthetical and can be accepted without other interventions on the head.

4 Surface Absorber : Continuous Emission or Long Pulses (>500 µsec) Surface Absorber : Short Pulses (<500µsec ) Laser beam Thermocouples Laser beam Thermocouples Cooling Cooling Light penetrates through within a thin layer of optically absorbing refractory materials (10-40µm thick ). Generated heat flows through substrate to thermocouples and cooling system. Light penetrates within the same thin layer of optically absorbing material, as previously shown. During the short laser pulse duration, a sudden amount of heat is generated but it cannot flow through substrate. Major damages to absorbers may occur. Volume Absorbers offer far better performances. B-Volume Absorbers-When heads with surface absorbers are used to measure lasers which deliver short time pulses ( lower than microseconds), heat has no time to flow and to be removed within the duration of the pulse length. Radiation remains deposited within in a thin surface layer where it generates a sudden overheating of the absorbing material and where the excess of energy will often cause ablation. In those cases the technology of volume absorption is used, where a gradual, exponential decrease of radiation intensity occurs as it penetrates into the material. Total absorptions are obtained over 0.5-2mm depths rather than few microns: the consequence is a better distribution of energy and a far lower local temperature increase. Various types of glasses and ceramics are used by LaserPoint to cover the UV-C range ( nm), the UV-A ( nm) and the VIS-NIR (BB absorber from 400nm to 3µm).Those absorbers can withstand peak powers of GW/cm 2 and energy densities up to 30J/cm 2. Volume Absorber : Short Pulses (<500 µsec) Laser beam Thermocouples Cooling Light penetrates and is absorbed by a thick layer of gradually absorbing materials (1-2 mm thick). Heat is generated within a volume and safely flows through substrate to thermocouples and cooling system. Volume absorbers can measure very short pulses and high energies much better than surface absorbers. Detector-to-Monitor Intelligent Interfacing Each detector head is a unique device and has its own specifications; for example, sensitivity or the voltage output per incident W or Joule of laser power or energy, is different from head to head. Its exact value is derived by calibration and calibration data have to be available to the readout unit to provide accurate readings. Other parameters, like response times, are also specific for a kind of head and the monitor must have those values to provide suitable speed-up of readings. These are examples of information that each readout unit must get, once a detector is linked. The question then arises on how to supply the monitors with additional, specific information, like those mentioned in the examples.

5 All detectors manufactured by LaserPoint come with a DB-15 connector that houses an E2PROM where all relevant parameter of detectors are stored. It s LaserPoint Intelligent Identification System (IIS) : the detector automatically identifies itself to the monitor and stored data are supplied. The monitor knows what to do, whether it is a 3W or a 6KW head. This technology has another advantage, with a relevant budget impact: all detector heads from LaserPoint can be easily interchanged with any of the monitors and one single readout can be used with all detectors in the lab. Selecting a Power or Energy Measurement Solution Measuring power or energy can be done in many different ways and to obtain either basic or complex information. In the majority of applications it is done by the commonly known power/energy meters, by laser probes or OEM sensors. In each case the finality may the same (e.g. knowing the laser power) but real, final needs may be very different, as well as their consequent economical aspects. A power/energy meter is made of a detector linked to a monitor via a special connector, storing all relevant data concerning the head. The monitor can work as a stand alone unit displaying the power/energy values and other information and can be connected to computers or chart recorders. Power/energy meters are high end instruments whose performances may vary with the number of features or complexity of the overall setup. Prices will follow accordingly. They are measurement instruments, the which thing means that they have to undergo to classes of precision, must have tight values of repeatability, need to be periodically re-calibrated (at least once a year) to trace their performance. For powers exceeding W the heads need an internal cooling system which could be a fan extracting heat from dissipating fins or water running through channels carved into the head. This is because power/energy meters must work continuously for long periods of time facing the laser beams, even many KWs, without problems. Their reliability and capacity to work indefinitely at the maximum powers or energies makes them the ideal instrument for applications like: -Measurement of laser or laser system stability -Alignment of laser cavity -Alignment of optical setups -Measurement of losses -Derive statistical information on laser behavior -Measure the power/energy ratio between 2 optical paths Doing all this is only possible by the association of a properly cooled detector with a complex electronics which reads the row data and elaborates/displays the measurements. Once the measurement session is over, the equipment can be easily removed and used elsewhere, with another laser or system. This is not so with OEM detectors. OEM detectors use the same sensors of power/energy meters embedded in simplified housings; they respond to the need of laser manufactures (in the majority of cases) to have a continuous monitoring of their sources and are permanently fixed into the laser head or the laser machine. But we are now talking of monitoring and not fine measurement: the associated electronics is in general very simple and limited to convert the sensor output into a signal manageable by the laser control unit. The power/energy value is displayed, maybe after basic signal treatment (e.g. the speed-up of response time) but no significant elaboration is made. Measurements are accurate and repeatable but the display of information is used to preset the power/energy levels necessary for an application, verify that set levels remain as fixed and no problems occur on the machine. Laser Probes only read power. They make a measurement in a fixed time period and are used to make time-to-time controls at the source exit, at the working area or before/after an optical component to check its losses. Probes simply tell which is the power level at the time of measurement, like a photo camera provides the picture of a shot taken at a certain instant; on the contrary power/energy meters can be imagined as movie or video cameras that show a real time and continuous evolution. For the above reasons probes cannot be used for alignments, monitoring of stability or provide statistical information which all require a continuous use. They are low cost devices and, until the introduction of LaserPoint s Cronos and FIT series with their patented measurement and acquisition techniques, the market was only offering poorly repeatable and precise instruments. FIT and Cronos have been the real breakthrough in this kind of measurement with the reduction of reading time (lowered from 20 sec or more to 4sec and 8sec), the possibility of making several measurements without cooling and the complete automatism of measurement which makes them independent from errors generated by wrong timings. All these innovations have now brought those probes to have performances comparable to power meters (e.g. the FIT instruments have the same capacity of a power meter to repeat measurements with a ±1% error bar).

6 LP-EXPLORER: the Detector Finding Program On the web or on the CD ROM with your catalogue Our new EXPLORER program will let you find, in the easiest way, the proper heads that meet your measurement needs. Just by entering the laser parameters EXPLORER will calculate the power or energy densities specific for that beam. It will finally relate these values, together with the other laser data and available detectors, to define and display which heads, monitors and coatings can be used. EXPLORER can be either downloaded from the web or from the CD-ROM with your catalog. From the Catalog CD: go to Start>Run>X:\LP-Explorer\setup.exe (where X stays for the CD-rom drive number).click OK and follow the instructions. After installation is completed, you may run the Explorer application from your desktop. Using the Explorer program is then all easy. Select There are a few initial steps to be performed before entering the beam parameters: 1) -specify the laser type: CW or Pulsed. 2) -indicate the beam shape. Heads are chosen considering their sensitive diameter always to be at least 16% larger than the beam itself; infact, most of times beam sizes are specified at 1/e 2, leaving a lot of energy-which must be taken into account- available outside the nominal size. 3)If Pulsed has been selected, the type of measurement to be performed has to be chosen, then: in Only Power the program will find heads and monitors which will measure only the average power. Vice versa, by selecting Power & Single Pulse Energy the program will decide which heads & monitors are available to measure both the energy of a single pulse and average power; for a correct measurement of avg power the repetition rate has to be > 3 Hz. 4)The last selection to be done is the kind of desired product: if the application involves long term measurements, laser alignments, the necessity of making statistics on measured values, etc then chose Power & Energy Meter. If the application is only a periodic check of laser power, then a LaserProbe is probably what better fits your needs.

7 Input Beam Parameters, Explore and Reset Data keys In this frame you ll need to enter your beam data with the appropriate measurement units. For a CW laser you will only need to insert Beam Diameter, Wavelength and Max Power. For a Pulsed laser it is necessary to add Pulse Width, Repetition Rate and Max Energy. Once all boxes have been filled, just click on the Explore key to obtain all information. If another type of measurement has to be done, e.g. at another wavelength, you can refresh the screen by clicking on the Reset Data key LP Explorer Results Panel Derived Beam Parameters This frame shows several important calculated beam parameters derived from your input data and will give a synthetic, yet exhaustive, picture of your beam. Available Heads& Coatings, Damage Threshold at: All detectors that fit with specifications for your beam parameters are shown and, to simplify selection, head types are separately listed in their various versions of coatings or absorbers. Aside the head model is reported the corresponding level of risk of damage for that coating/ absorber when subject to the inserted laser parameters. This value is expressed as a % of the damage threshold. It will undoubtedly result that some detectors may be closer to the damage threshold than others : always prefer a head which is below the 50% of damage threshold. This will put the coating on the safe side from hot spots and compensate from laser modes.

8 To proceed on your selection you may single click on each head model to open the Power/Energy Resolution with Monitor frame; a double click will open a pdf file showing both specifications and a mechanical outlook for each head of interest. Some additional selection criteria are more personal and depend on the way the head will be used or the kind of application; for example LaserPoint manufactures a series of compact heads designed to work intermittently or for short periods. They are the heads with double code (e.g. the A-40/200 series) which can extend their measurement range, repeatedly but intermittently, These heads have a temperature sensor and, when associated with PLUS/ LPM monitors, can be used until a COOL message is displayed. Power/Energy Resolution with Monitor This frame displays another important information which has to be taken into account when selecting a detector: the power or energy resolution provided by a complete measurement setup. Resolution depends on the noise of both monitor and head and can be seen as the least value which can be read having a practical meaning. Whenever a monitor is then available for the selected detectors ( if not, a n.a.. is displayed), the box underneath each monitor model reports the achievable resolution. Always consider what the frame reports, both for determining which monitor has to be used, but mostly to be aware of the real minimum values ( at least 10 times the resolution) of Power/ Energy which can be read. Coating and Absorber Curves Characteristics The program also lists the absorption and damage threshold curves for coating and absorbers used by LaserPoint. Once you have selected a head with its coating or absorber, you may click on the side key to visualize, as pdf files, the complete performance of the coating/ absorber itself. This additional check can be very useful if the head is intended to be used at other wavelengths or with different pulse lengths. Print To print a hard copy of the screen, just click on the Print Key

9 Calibrations at Laser Point NIST and PTB Traceability Sensitivity, or the voltage signal delivered by a detector as a function of striking laser power or energy, is different form detector to detector for different reasons one of which is the spectral response of absorbing coatings: the percentage of absorbed radiation is never % at any wavelength, but is a lower value which changes with the wavelength itself. Sensitivity undoubtedly depends also on manufacturing variables but it also happens that power and energy meters change their properties with time, as environmental factors usage in particular-, degrade or damage parts critical for an optimum performance. In order to grant precise measurement accuracy, LaserPoint supplies each of his instruments calibrated before delivery to the highest level of accuracy, with traceability to the National Institute of Standards and Technology (NIST) Laboratories in Boulder, Colorado (USA) and the Physicalisch-Technische Bundesanstalt (PTB) in Berlin (Germany). All LaserPoint detectors are subject to this Nist and PTB traceable calibrations and a Certificate, reporting the list of NIST/ PTB standards and instruments used in the calibration procedure, is supplied to prove it. To ensure that accuracy and performances of laser power and energy meters remain intact over the time, a regular schedule of calibration and preventive maintenance is needed. An industry standard is to recalibrate once a year: units can be shipped back at LaserPoint where, at a modest fee, a general check-up and recalibration of the detector will be done. Calibration Capabilities in LaserPoint LaserPoint owns a number of laser sources which are used for in-house calibration ; these sources cover PTB Linearity Measurements for W-0 powers up to 300W and include pulsed lasers. LaserPoint furthermore relies on contracts for the use of 0 multikilowatt lasers and other sources with nearby 800 Scientific Institutes for tests and calibrations at high 600 powers. A number of detector heads, calibrated by the 400 wavelength at NIST and PTB, are used as Standards 200 for calibration procedures. 0 To trace linearity even at high power levels, heads have been calibrated over their entire working range up to > Ref. Power (W) 1KW for CO2 and 300W for Yag. All measurements, made by PTB and NIST, show high linearity of LaserPoint detectors and that their behaviour is well within standard specifications (3%). On the wavelength range 250-1nm LasePoint can optionally supply calibrations at any wavelength based on NIST traceable spectroradiometer measurements. Measured Power (W) Wavelength 532nm 633 nm 980nm 1064nm 1064nm 10.6microns Type CW CW Pulsed +CW Pulsed CW CW

10 Laser Power and Energy Heads How to read products ID code and select a detector head To ease and speed up your selection we have assembled codes that synthetically describe the detectors; we just ask you to complete these codes adding the type of measurement and the wavelength of calibration. The complete code, to be used when asking for quotes or when ordering, is then straightforward and gives an accurate, synthetic and a no-doubt description of the heads and the way it is going to be used, which helps LaserPoint to serve you better and faster. Head codes, as you will find on the catalogue or given by the LP Explorer, report a string which synthesizes the head basic features : 1-Firstly we identify the cooling type. A stays for air cooling (which can either be by convection or forced: please check on the single head specs ); W stays for water cooling. 2-Then we identify the full scale power (e.g. 200 means that the head can withstand up to 200W). Some of the new heads have a double code separated by a /. (egg 40/200) : those are heads with sensors capable to withstand many times the max nominal power, in case of short term use. In these cases the first digits identify the maximum power on continuous operation; the latter digits report the max power when the head is used for a limited period. 3-The sensitive Diameter (D XX) is also displayed.some detectors may have the same power but different acceptance areas as they have been developed for different applications. Chose which fits better for your case remembering that nominal beam diameters are always given to include the 86% (1/e 2 ) of the beam energy. Real beams are larger! 4- The last digits show which coatings or absorbers types available for each type of head. Sometimes more than one coating is available for that head. Select the model with the most suitable coating for your application: egg HCB. For any doubt refer to coating specifications or take advantage of the LP Explorer. The following are the additional information we ask you to add: 5- Measurement Mode : detectors can be configured to work as Power Meters (P), as energy meters (E) or both (P+E). When constructing the code, specify which are the measurement modes of your necessity : e.g. -E 6-Calibration Wavelength :select from the tables in the Ordering Information the kind of available calibration wavelengths and add it to the code: e.g. -VIS Example of a Complete Code: A-40/200-D40-HPB-P-Y Calibration Wavelenght: Y (Nd.Yag) Measurement Mode:P (Power only) Coating Type: HPB (High Power Broadband) Sensitive Dia : 40mm Max. Pwr. LongTerm :40 W / Max. Pwr. Limited Period:200 W Air Cooling

11 Excimer Absorber Heads for Pulsed Lasers Quick Reference Tables -Models up to 600W for high power industrial excimer lasers -Large Area Detectors to 60 mm -Sensitive thermopile sensors for power detection down to 15mW -The highest resistant coatings for UV : up to 20MW/cm 2 and 0.5J/cm 2 -EMI rejection -NISTand PTB (Physikalisch-Technische Bundesanstalt) traceability Head Code Power Range (1) Max. Peak Power Density (2) Energy Range (3) Useful Aperture Spectral Range Cooling A40-D25-EX 10mW - 60W 70MW/cm 2 200mJ - 40J Ø25mm µm (10.6µm) convection A40-D40-EX 10mW - 60W 70MW/cm 2 200mJ - 40J Ø40mm µm (10.6µm) convection A40/200-D40-EX mw - 200W 70MW/cm 2 1 J - 200J Ø40mm µm (10.6µm) convection A40/200-D60-EX mw - 200W 70MW/cm 2 1 J - 200J Ø40mm µm (10.6µm) convection A-200-D40-EX mw - 250W 70MW/cm 2 1 J - 200J Ø40mm µm (10.6µm) forced air A-200-D60-EX mw - 250W 70MW/cm 2 1 J - 200J Ø60mm µm (10.6µm) forced air A300-D60-EX mw 450W 70MW/cm J - 350J Ø60mm µm (10.6µm) forced air A600-D40-EX mw -800W 70MW/cm 2 3 J -600J Ø40mm µm (10.6µm) forced air NOTE: (1) Max Values for Intermittent Power Use (2) -UV, with 4 nsec pulses (3) - Max. Values with long pulses Use for the Following Applications, Average Power from High Power Excimer Lasers Long Term Power Monitoring Measurement of Laser Stability Statistical Information on Laser Beam: -Min & Max Value -Standard Deviation -Average Fields Marking (glass, cables, polymers, etc.) Laser Ablation and Annealing Lithography Flat Panel Display Nozzles (fuel injection, inkjet, glass) Dermatology Refractive Surgery and Sources 190nm, 258nm, 351nm Tea Lasers Copper Vapors These Detectors Can Be Associated to : Plus : see specs on the Displays, Controls and Software section of this catalog PC-Link : see specs on the Displays, Controls and Software section of this catalog LPM : see specs on the Displays, Controls and Software section of this catalog PLUS-SOFT and LPM-SOFT : see specs on the Displays, Controls and Software section of this catalog

12 Specifications Adj. TYPICAL LASERS: Excimers Copper Vapor Co2 TEA 3 th and 4 th A-40-D25-EX Ø25 10 FEATURES: * Average Power & Single Pulse * 10mW 60W or mj 40J * Large Area * Hard Excimer Coating Max. Continuous Power : 40 W Intermittent Power Use: 60W (a) Power Resolution: 10mW (with Plus Monitor) Max. Energy : 40 J (long pulses) Energy Threshold : 200 mj Available Absorber Types. Excimer absorber Wavelength Range : µm, 10.6µm (b) Max. Average Power Density : 2 KW/cm 2 Max. Pulse Energy Density: See Absorption and Damage Thresholds Graphs Calibration Accuracy (%): ±3% Response Time with Display (0-90%): <1 sec. Linearity : ±1% (c) NEP(Noise Equivalent Power) : 5 mw Sensitive Diameter : 25mm Cooling: Convection Notes: a. 2 minutes max b. Calibrated up to 10.6µm. c. Detector centrally 50% of useful surface TYPICAL LASERS: Excimers Copper Vapor Co2 TEA 3 th and 4 th A-40-D40-EX Adj. Ø40 10 FEATURES: * Average Power & Single Pulse * 10mW 60W or mj 40J * Large Area Max. Continuous Power : 40 W Intermittent Power Use: 60W (a) Power Resolution: 10mW (with Plus Monitor) Max. Energy : 40 J (long pulses) Energy Threshold : 200 mj Available Absorber Types. Excimer absorber Wavelength Range : µm, 10.6µm (b) Max. Average Power Density : 2 KW/cm 2 Max. Pulse Energy Density: See Absorption and Damage Thresholds Graphs Calibration Accuracy (%): ±3% Response Time with Display (0-90%): <1 sec. Linearity : ±1% (c) NEP(Noise Equivalent Power) : 16 mw Sensitive Diameter : 40mm Cooling: Convection * Hard Excimer Coating Notes: a. 2 minutes max b. Calibrated up to 10.6µm. c. Detector centrally 50% of useful surface

13 A-40/200-D40-EX Adj. Ø40 TYPICAL LASERS: Excimers Copper Vapor Co2 TEA 3 th and 4 th 10 FEATURES: * Average Power & Single Pulse * mw 200W or 250mJ 200J * Convection Cooled *Hard Excimer Coating Max. Continuous Power : Intermittent Power Use: Power Resolution: Max. Energy : Energy Threshold : Available Absorber Types. Wavelength Range : 40 W 200W (a) mw (with Plus Monitor) 200 J (long pulses) 1 J Excimer absorber Max. Average Power Density : 2 KW/cm 2 Max. Pulse Energy Density: Calibration Accuracy (%): ±3% Response Time with Display (0-90%): Linearity : NEP(Noise Equivalent Power) : Sensitive Diameter : Cooling: Notes: µm, 10.6µm (b) See Absorption and Damage Thresholds Graphs <1 sec. ±1% (c) 20 mw 40mm Convection a. 2 minutes max b. Calibrated up to 10.6µm. c. Detector centrally 50% of useful surface Adj. A-40/200-D60-EX TYPICAL LASERS: Excimers Copper Vapor Co2 TEA 3 th and 4 th 55 Ø60 75 FEATURES: * Average Power & Single Pulse * mw 200W or 250m J 200J * Convection Cooled *Hard Excimer Coating 10 Max. Continuous Power : 40 W Intermittent Power Use: 200W (a) Power Resolution: mw (with Plus Monitor) Max. Energy : 200 J (long pulses) Energy Threshold : 1J Available Absorber Types. Excimer absorber Wavelength Range : µm, 10.6µm (b) Max. Average Power Density : 2 KW/cm 2 Max. Pulse Energy Density: See Absorption and Damage Thresholds Graphs Calibration Accuracy (%): ±3% Response Time with Display (0-90%): <1 sec. Linearity : ±1% (c) NEP(Noise Equivalent Power) : 20 mw Sensitive Diameter : 60mm Cooling: Convection Notes: a. 2 minutes max b. Calibrated up to 10.6µm. c. Detector centrally 50% of useful surface

14 Adj. A-200-D40-EX Ø40 10 TYPICAL LASERS: Excimers Copper Vapor Co2 TEA 3 th and 4 t h FEATURES: * Average Power & Single Pulse * mw 250W or 250 mj 200J * Fan Cooled *Hard Excimer Coating Max. Continuous Power : Intermittent Power Use: Power Resolution: Max. Energy : Energy Threshold : Available Absorber Types. Wavelength Range : 200 W 250W (a) mw (with Plus Monitor) 200 J (long pulses) 1 J Excimer absorber Max. Average Power Density : 2 KW/cm 2 Max. Pulse Energy Density: Calibration Accuracy (%): ±3% Response Time with Display (0-90%): Linearity : NEP(Noise Equivalent Power) : Sensitive Diameter : Cooling: Notes: µm, 10.6µm (b) See Absorption and Damage Thresholds Graphs 1 sec. ±1% (c) 20 mw 40mm Forced Air (d) a. 2 minutes max b. Calibrated up to 10.6µm. c. Detector centrally 50% of useful surface d. Power supply (110VAC/220VAC) included for internal 5W, 12VDC fan Adj. A-200-D60-EX TYPICAL LASERS: Excimers Copper Vapor Co2 TEA 3 th and 4 th Ø60 10 FEATURES: * Average Power & Single Pulse * mw 250W or 250mJ 200J * Fan Cooled *Hard Excimer Coating Max. Continuous Power : 200 W Intermittent Power Use: 250W (a) Power Resolution: mw (with Plus Monitor) Max. Energy : 200 J (long pulses) Energy Threshold : 1 J Available Absorber Types. Excimer absorber Wavelength Range : µm, 10.6µm (b) Max. Average Power Density : 2 KW/cm 2 Max. Pulse Energy Density: See Absorption and Damage Thresholds Graphs Calibration Accuracy (%): ±3% Response Time with Display (0-90%): 1 sec. Linearity : ±1% (c) NEP(Noise Equivalent Power) : 20 mw Sensitive Diameter : 60mm Cooling: Forced Air (d) Notes: a. 2 minutes max b. Calibrated up to 10.6µm. c. Detector centrally 50% of useful surface d. Power supply (110VAC/220VAC) included for internal 5W, 12VDC fan

15 Ø60 A-300-D60-EX TYPICAL LASERS: Excimers Copper Vapor Co2 TEA 3 th and 4 th Adj. FEATURES: * Average Power & Single Pulse * mw 450W or 400m J- 300J * Very Large Area * Fan Cooled Max. Continuous Power : Intermittent Power Use: Power Resolution: Max. Energy : Energy Threshold : Available Absorber Types. Wavelength Range : 300 W 450W (a) mw (with Plus Monitor) 300 J (long pulses) 1.5 J Excimer absorber Max. Average Power Density : 2 KW/cm 2 Max. Pulse Energy Density: Calibration Accuracy (%): ±3% Response Time with Display (0-90%): Linearity : NEP(Noise Equivalent Power) : Sensitive Diameter : Cooling: Notes: µm, 10.6µm (b) See Absorption and Damage Thresholds Graphs 3.5 sec. ±1% (c) 28 mw 60mm Forced Air (d) a. 2 minutes max b. Calibrated up to 10.6µm. c. Detector centrally 50% of useful surface d. Power supply (110VAC/220VAC) included for internal 5W, 12VDC fan A-600-D40-EX Ø TYPICAL LASERS: Excimers Copper Vapor Co2 TEA 3 th and 4 th Adj. FEATURES: * Average Power &Single Pulse * mw 800W or 700mJ - 600J * Large Area * Fan Cooled Max. Continuous Power : 600 W Intermittent Power Use: 800W (a) Power Resolution: mw (with Plus Monitor) Max. Energy : 600 J (long pulses) Energy Threshold : 3 J Available Absorber Types. Excimer absorber Wavelength Range : µm, 10.6µm (b) Max. Average Power Density : 2 KW/cm 2 Max. Pulse Energy Density: See Absorption and Damage Thresholds Graphs Calibration Accuracy (%): ±3% Response Time with Display (0-90%): 3.5 sec. Linearity : ±1% (c) NEP(Noise Equivalent Power) : 80 mw Sensitive Diameter : 40mm Cooling: Forced Air (d) Notes: a. 2 minutes max b. Calibrated up to 10.6µm. c. Detector centrally 50% of useful surface d. Power supply (110VAC/220VAC) included for internal 5W, 12VDC fan

16 Absorption and Damage Threshold Curves General Absorption Curves EXC Absorption % Wavelength (microns) Pulse Energy Ratings and Damage Thresholds 00 Energy Density (J/cm2) Damage Safe Operation EXC 0.1 1E-10 1E-8 1E-6 1E-4 1E-2 1E+0 Pulse Width (s)

17 Ordering Information Item (please add all codes when ordering) Code CW thermopile head with excimer coating up to 40 W 25mm aperture-air cooled + Light duty stand CW thermopile head with excimer coating up to 40 W 40mm aperture-air cooled + Light duty stand CW thermopile head with excimer coating up to 40 W (200W 2min) 40mm aperture-air cooled + Light duty stand CW thermopile head with excimer coating up to 40 W (200W 2min) 60mm aperture -air cooled + Light duty stand CW thermopile head with excimer coating up to 200W-40mm aperture - forced air cooling + Light duty stand CW thermopile head with excimer coating up to 200W-60mm aperture - forced air cooling + Light duty stand Large Area thermopile head with excimer coating up to 300W-60mm aperture -forced air cooling + Heavy duty stand and base Large Area thermopile head with excimer coating up to 600W-40mm aperture -forced air cooling + Heavy duty stand and base Measurement Mode Power Measurement, only Energy Measurement, only Power & Energy Calibration Wavelengths: 355nm (standard) 10.6 µ (standard) Example of Complete Code : A-40-EX-P-UV A-40-D25-EX A-40-D40-EX A-40/200-D40-EX A-40/200-D60-EX A-200-D40-EX A-200-D60-EX A-300-D60-EX A-600-D40-EX -P -E -PE -UV -C

18 Applications of Power and Energy Heads Measurement of long term stability Long term verification of stability, necessary for example for the final validation of a laser source, is made by directly placing a power meter head, e.g. associated to the PLUS monitor, in front of the laser. The main screen of PLUSSOFT shows the long term behaviour of up to 12 hours. Plus and PlusSoft also have the possibility to set hi and low alarm thresholds. Laser Alignment of laser cavities Alignments require continuous tweaking of cavity mirrors: during these actions values change very quickly and understanding whether tuning is improving or not need a proper tool. Digital displays, with their fast running numbers are very un-easy; on the contrary, analog displays with their moving needle require a lot of attention to catch the value. Bargraphs are of great help to provide an immediate feeling of the direction of alignment, like in LaserPoint PLUS:, to have a fast perception of tuning direction at the same time maintaining the possibility to read the reached value. Laser Alignment of optical set-ups Optical losses can be introduced by a number of reasons, like the non correct angular positioning of elements or by damaged components; more often a sensitive decrease of throughput can be reached by misalignments or simply by summing individual losses of optical components. A power/energy meter positioned along the beam path, permitting correct alignments and verification of losses, optimises yield and efficiency of the optical system. Laser Measurement of losses Verification of reflectivity, transmission and losses of beam splitters, filters and other optical elements can be done by inserting a power/energy meter in front or behind the component. Dynamic changes, like modification of behaviour or performances under the action of temperature variations, can be also monitored. Laser T R

19 Statistical measurements of laser or laser machine behaviour Statistical measurements are used for monitoring quality aspects of a source, a laser machine or set-up. Having for references heads bearing a NIST (National Institute for Standard and Technology) and PTB (Physikalisch-Technische Bundesanstalt) traceable calibration, data can be used for internal files, for quality reports, can be added to manuals or given to customers. All relevant statistical information as Current Value, Min &Max Values, Average, RMS Stability, Standard Deviation are supplied by the PLUSoft on measurement periods as long as required. For easiest handling, all statistical data can be transferred and saved on files or printed Laser

20 Displays, Controls and Software Selecting a meter for the application The first step in defining a measurement system is to choose the detector needed for a specific application. The following step is the meter selection which may be based on the following three basic considerations: a)-where the meter is going to be used. For example, if the operator is a service engineer who spends most of his time in the field, then he needs fully portable and rugged equipment for quantitative measurements and laser alignment. Laser Point s PLUS is the small, battery operated meter designed for those applications. A different case is when the laser machine needs an internal monitoring system which will be used to verify the constancy of preset parameters, to predict maintenance of beam line components etc. For these applications the tool is the Laser Process Monitor ( LPM) b)-which are the needed additional features. If the requirement is the use of a power meter for the final validation of a laser system before its delivery to the customer, it may be then necessary to do advanced statistical analysis.laser Point s PLUS-SOFT or LPM-SOFT powerful analysis software extend measurement capabilities c)-foresee future developments. Perhaps in a near future a new laser machine will be purchased in the Company and the necessity to use different heads, e.g. for high and low powers, will arise. The PLUS offers this possibility, since it mates with all LaserPoint detectors, via its IIS (Intelligent Identification System) The following at-a-glance table will help in a first selection. Features & Capabilities PLUS LPM-OEM LPM-CE PC-LINK Power, Energy,Heads Power, Energy,Heads Detectors OEM Laser Probes OEM Laser Probes Data Display LCD Screen Machine s PLC PC & Laptop Outputs RS-232, 0-10V and 4-20mA USB RS-232 or USB 0-2V Analog Out Analog Out on LPM-SOFT screen and 220V-10A Alarm Relay Power, Energy,Heads OEM Laser Probes Process Alarms on PLUS-SOFT screen Wavelenght Selection Y N N Tuning Function User's Calibration Capability Min/Max. Full Scales digital and on PLUS- SOFTscreen digital and on LPM- SOFTscreen on PCLink-SOFT screen on PCLink-SOFTscreen Y Y Y 0.1mW-10KW 1mJ-300J 0.1mW-10KW 1mJ-300J 260xx110m (LPM-OEM) Dimensions 150x105x45mm 305x160x70mm(LPM-CE) Operation Battery and 12VDC 220VAC and 110VAC 0.1mW-10KW 1mJ-300J 113 x 56 x 35 mm External Power Supply Not required

21 Laser Power and Energy Meter: the PLUS The PLUS model is a meter for advanced power and energy measurement that mates to all LaserPoint detectors via a proprietary Intelligent Interface System (IIS )connection. It is sufficient to plug the head connector into the meter port to get a calibrated instrument, already configured for the measurement. One of the great advantages of the IIS connection is that, should a new head be added to the lab equipment or to the system, the existing monitor can be used with that new head; in other words any Laserpoint detector can be associated to a PLUS monitor if measurement requirements become different. The PLUS then converts the output voltage signals from detectors into accurate readings of power and energy or supplies other valuable information by means of its additional software. The PLUS has been structured to match to a very broad range of applications and any customer budget. Unbeatable Price to Performance Easy and immediate: The PLUS is the most versatile measurement monitor for thermal heads existing on the market today. Its price and performance are absolutely outstanding, since it has been specifically imagined and designed to be the tool for laser measurement available to every laser operator. The PLUS can be plugged to any of LaserPoint detectors by means of its standard Intelligent Interfacing System (IIS). The instrument can be governed just by means of three soft-touch keys: -ON/OFF (Zero). During a measurement session, the key will also Zero stored measurement values and display. -T/P. Gives access to the Tuning Function and the Power Measurement Function. -E. The E key provides access to the Energy Measurement Function. The mw/ mj leds, associated to the low Power/Energy Measurement Functions, are only enabled by information stored within the detector E 2 PROM. Power, Energy, FIT Operational Modes: PLUS can work on different operational modes. It can be used as a power meter, as an energy meter or as a power probe up to 6KW, when working with the FIT heads. The selection is automatically made by the monitor when it reads the detector E 2 PROM, when the unit is switched on. Temperature Compensation: Ttemperature compensation is made after an incoming signal from a temperature sensor located within the detectors, by the PLUS to linearize the head response and advise, with a warning message on the display, when the head has overtaken its max allowable temperature. External Interfacing: PLUS can dialog with the external PCs, plotters, etc via its Analog Output (0-2 Volts) or RS232 digital interface, which are provided as standard. Tuning: Through this function, a high resolution laser tweaking can be done. The existing power level is then displayed, together with the bargraph, positioned at its center; it will move downward or upward depending on tuning. The smaller digits shown on the display are the variations, in percent, from the initial power value Additional features The E 2 PROM, housed within the IIS (Intelligent Interfacing System) connector, stores wavelength correction values based on spectral data measured from each coating or absorber. The PLUS display will show : EXC : for the UV and excimer laser range ( nm) VIS: for the visible range ( nm) LD: for the Laser Diodes range ( nm) Yag: for the Nd-Yag wavelength at 1064 nm Erb: for the Erbium wavelength at 2943 nm

22 CO2 : for the CO2 wavelength at 10600nm UCF:( User s own Re-Calibration Factor) The User Calibration Factor gives customers the possibility to modify the value of original calibration sensitivity from 01.% up to 999.9% (or from 1/0 up to 10 times). It can be selected when scrolling for the wavelengths The UCF can be used : -in case of light damages on coatings -in case of detection after partializing devices (e.g. filters, beamsplitters, mirrors) to track the main beam -have measurements aligned to other references The UCF is effective on each measurement mode of Plus (power, energy, Fit). PLUS: Technical Specifications Power Meter Mode Power Ranges: Resolution: Response Time head) Energy Meter Mode Power Range: Resolution: Response Time: head) FIT Mode Power Ranges: Resolution: Response Time: 1mW to 10kW 0.5 for any Full Scale <1-5 sec. ( depends on each specific 1mJ to 300J 0.5 for any Full Scale <1-5 sec ( depends on each specific 1mW to 10kW 0.5 for any Full Scale 4 sec (final value) General Digital Display: 4-digit LCD readout Monitor accuracy: ±0.5% Scales: 3 scales (00.00 / / 0000),head dependent with 0.5 resolution Analog Output: 0-2V ±1.0% Digital Outputs: RS-232 on DB9Connector or USB Temperature Compensation Over-Temperature Alarm Overflow Alarm Overload Alarm : Input voltage: 12VDC Adapter Batteries: 2 LR6 (AA -1.5 V) Battery life: 250 hours ; OFF State one year Dimensions (mm) : 150 (W) x 105 (H) x 45 (D) Weight: 500g Tuning -Displays a Digital Bargraph for Tuning Direction -Displays Actual Power Value -Displays Variations (as %) form Tuning Initial Value Operating environment: Storage Temperature:-10 to 60 ºC Range of Use :5 to 45 ºC Reference Conditions : 21 ± 4 ºC ;RH 20-80% Selections: Wavelengths EXC : UV and excimer laser ( nm) VIS: Visible ( nm) LD: Laser Diodes ( nm) Yag: Nd-Yag (1064 nm) Erb: Erbium (2943 nm) CO2 : CO2 (10600nm) UCF: User s Own Re-Calibration Factor Ordering Information Item (please add all codes when ordering) Plus :Low Cost-Hi performance Digital Power & Energy meter with RS232 interface & analog output, tune mode and 6 lambda corrections PLUS-USB Low Cost-Hi performance Digital Power & Energy meter with USB interface & analog output, tune mode and 6 lambda corrections; SW included. Accessories and Options SW for statistical analysis+ RS232/Analogue cables (optional for Mod PLUS) Carrying case for PLUS 120VAC or 240VAC/12VDC Power supply Example of Complete Code : PLUS+PLUSOFT+Case Code PLUS PLUS-USB SW+ CASE+ PS

23 Smart Head to USB Interface: the PC-LINK Your Laptop or PC Converted Into a Power/Energy Meter LaserPoint introduces the PC-LINK, a smart head to USB interface that converts any PC or laptop into a real, powerful laser power or energy meter. To make it work it is sufficient to install the software, connect the head to the interface unit and this latter to the USB port of a PC. No external power source is needed. This sophisticated monitor is plug and play with all LaserPoint smart heads and has been designed for service and laboratory applications offering the convenience, flexibility and value of computer-based operations. PC-LINKs are supplied with LaserPoint s user-friendly communication software package. The Rich and Flexible Monitor The very compact size and low weight of PC-Link, together with its advanced features make this monitor the ideal partner for service applications or laboratory use. The PC-LINK is also the candidate for use in laser machines, in particular when associated to LaserPoint s FIT detectors that work up to 6KW without the need of water cooling. The use of PC-Link is straightforward. The unit will recognize the power/energy head as soon as it is plugged-in; furthermore, the PC-LINK will use its anticipation circuitry to insure a fast response and will auto-calibrate by using the data stored in the intelligent connector (IIS) to provide the most accurate measurement. Another feature is the access to the User s Own Calibration Factor (UCF) and a X10 gain for enhanced measurement flexibility (eg low power measurement to 20mW fs). The software supplied with the PC-Link allows to measure, analyze with full statistical functions (Min., max., mean, and standard deviation) and record power and energy from all LaserPoint heads without the need of a display. Data from each detector can be logged simultaneously to file. PC-Link: Technical Specifications Power Meter Mode Power Ranges: Resolution: Response Time head) 1mW to 10kW 0.5 for any Full Scale <1-5sec.( depends on specific Energy Meter Mode Power Range: 1mJ to 300J Resolution: 0.5 for any Full Scale Response Time: <1-5 sec ( depends on specific head) FIT Mode Power Ranges: Resolution: Response Time: 1mW to 10kW 0.5 for any Full Scale 4 sec (final value) GENERAL SPECIFICATIONS Software: Full Window application software Communication: Full Speed USB 1.1 Communication between Host Computer and PC-LINK Display: Computer Screen Data Storage: Limited by PC capacity Data Displays: Real time, Histogram, Statistics Additional Input Gain: 10X Dimensions 113 (L) x 56 (W) x 35 (H) mm Weight kg External Power Supply Not required Operating environment: Storage Temperature:-10 to 60 ºC Range of Use :5 to 45 ºC Reference Conditions : 21 ± 4 ºC ;RH 20-80% Tuning -Displays a Digital Bargraph for Tuning Direction -Displays Actual Power Value -Displays Variations (as %) form Tuning Initial Value Selections: Wavelengths EXC : UV and excimer laser ( nm) VIS: Visible ( nm) LD: Laser Diodes ( nm) Yag: Nd-Yag (1064 nm) Erb: Erbium (2943 nm) CO2 : CO2 (10600nm) UCF: User s Own Re-Calibration Factor Ordering Information Item (please add all codes when ordering) Smart head to USB interface: module to operate LaserPoint smart heads from PC USB ports. Comes with LaserPoint software Code PC-Link