905 nm Multi-Quantum Well Strained InGaAs Pulsed Laser Diodes PGA Series

Transcription

1 905 nm Multi-Quantum Well Strained InGaAs Pulsed Laser Diodes PGA Series Overview This series of devices employs elements from 75 µm wide single sources to four stacks of 600 µm wide elements. Using standard InGaAs quantum wells grown for 905 nm, this group of devices effectively replaces conventional double heterostructure GaAs- AlGaAs diodes in that wavelength range. Structural models have enabled design and production of multiquantum wells that provide a balance between 25 beam divergence in the perpendicular direction while retaining excellent stability of power output over the full MIL spec temperature range. For most applications, temperature compensation is unnecessary even at maximum duty (up to 100 KHz repetition rate). The structures are fabricated using metal organic chemical vapor deposition (MOCVD). This is a gaseous phase epitaxy process that provides for very precise control of the crystal layers so that near theoretical performance can be realized. With the addition of indium to the GaAs active regions (the quantum wells) the band gap can be controlled to produce lasing at 905 nm. Evaluations have demonstrated that this crystal is substantially more rugged than AlGaAs lasers. The point at which facet burn off occurs, ie the threshold of catastrophic optical damage, has been determined over a wide range of conditions. This information has been included in the data sheet to provide the system designer with up to 4 times normal operation for 10 ns wide pulses. Also beneficial is the extension of the rating to permit the use of 1µs pulses for single element devices. Recognizing that different applications require different packages, six standard package options are offered. Along with the traditional stud designs, 5.6, 9 mm and ceramic substrates are also available. As pulse widths have decreased and optical coupling has become more important, newer packages with reduced inductance and thinner, flatter windows have gained in popularity. For pulse widths below 5 ns, hybridization with drive circuitry is the only practical answer. Key Features and Benefits Peak power to 112 Watts at 150 ns pulse width Range of single element and stacked devices Up to 400% overdrive capability 25 beam divergence for single elements 83% power retention at 85 C 100 KHz operation with no power loss Overdrive capability to get up to 4x power Flexibility in customization for different applications Multiple choice of standard packages for various system designs RoHS compliant SENSOR SOLUTIONS D A T A S H E E T

2 The preferred package options on the list will normally be offered at lower cost and with shorter delivery times. To complete the information in this datasheet, many devices have been characterized over a wide range of conditions. Life testing has been conducted with excellent results between 30 and 200 ns far exceeding 10,000 hours of continuous operation. To keep the costs down, the standard devices are tested and burnedin under standard conditions. While the devices are warranted over the entire specification, for a quantity purchase, customers are advised to discuss their requirements in advance to accomodate any special test needs and achieve optimal yields. PerkinElmer Optoelectronics routinely supplies variants of the PGA series for military applications. Therefore, this range of diodes benefits from experience of over two decades of screening laser diodes to European and North American military specifications. Though the commercial products are not continuously screened, they are designed to meet demanding environmental conditions. Typical qualification of these parts would include: High temperature storage Hermetic seal Thermal shock Random vibration Acceleration Mechanical shock PerkinElmer Optoelectronics is pleased to advise and test to your specific environmental needs. Table 1. Maximum ratings Generic Data Peak reverse voltage, VRM Limiting Values 2 V Pulse duration, tw Single element 1 µs Multi-element 200 ns Duty factor, du 0.1% Temperature: Storage -55 C to 100 C Operating -55 C to 85 C Soldering for 5 seconds (leads only) +260 C Operating considerations The laser is operated by pulsing in the forward bias direction. The PerkinElmer Optoelectronics warranty applies only to devices operated within the maximum ratings, as specified. Power output exceeding the guidelines in Figure 7, even for single pulses, is likely to cause permanent burn-off damage to the laser facet and, consequently, a significant reduction in power. Operating the devices at increased duty cycles will ultimately and irreparably damage the crystal structure due to internal heating effects. Diodes are static sensitive and suitable precautions should be taken when removing the units from their antistatic containers. Circuits should be designed to protect the diodes from high current and reverse voltage transients. Voltages exceeding the reverse breakdown of the semiconductor junction are particularly damaging and have been shown to cause degradation of power output. Although the devices will continue to perform well at elevated temperatures for thousands of hours, defect mechanisms are accelerated. Optimum long-term reliability will be attained with the semiconductor junction at or below room temperature. Adequate heat sinking should be employed, particularly for the larger stacks and when operated at maximum duty factor. 2

3 Forward voltage The forward voltage of the device is a combination of a static voltage drop, the result of the band gap and material characteristics; a static series resistance, the result of the contact area dimensions and resistivity of the contact layers; and the inductive voltage drop, which is the result of the package inductance, the pulse rise time and the peak current. Voltages due to the inductive elements are additional and should be considered separately. The voltage drop of the laser die itself can be approximated by referring to the RDS value in the Characteristics Table and using the formula VLD = (RDS * if) + (# of elements * 1.29). Package inductance When narrow pulse widths are required, the system designer must take care that circuit inductance is kept to a minimum (note inductances on package list). Using the lower inductance packages will reduce the peak voltage required to obtain the desired drive current. For example, to obtain approximate Gaussian pulse shapes for the C and U packages: 1. PGAC1S12H tw = 40 ns Prr = 25 Khz tr = 20 ns if = 60 A LCPKG = 12 nh VL = LPKG x di/dt 1. VCPKG = 12 x 10-9 x 60/20 x 10-9 = 36 Volts 2. PGAU1S12H tw = 40 ns Prr = 25 Khz tr = 20 ns if = 60 A LUPKG = 5.0 nh VL = LPKG x di/dt 2. VUPKG = 5 x 10-9 x 60/20 x 10-9 = 15 Volts Note: These voltage drops are merely to overcome the inductance of the package and do not include the series package and chip static resistances. Other circuit elements typically increase voltage requirements to 3 x VPKG, therefore, the location of components to minimize lead lengths is critical. Table 2. Generic electro-optic specifications at 23 C MIN TYP MAX UNITS Wavelength of peak radiant intensity λ nm Spectral bandwidth, λ at 50% intensity points 5 nm Wavelength temperature coefficient.25 nm/ C Beam spread (50% peak intensity) Parallel to junction plane / 10 Degrees Perpendicular to junction plane _ Single element 25 Degrees Stacks 30 Degrees 3

4 Typical characteristics at tc = 23 C, tw = 150ns, du = 0.1% Table 3. Single chips Parameters PGAS1S03H PGAS1S06H PGAS1S09H PGAS1S12H PGAS1S16H PGAS1S24H PO at ifm Min 5.5 W 11.5 W 17.0 W 23.0 W 31.0 W 47.0 W Typ 6.2 W 13.5 W 19.0 W 26.0 W 35.5 W 54.0 W Number of elements Emitting area 75 x 1 µm 150 x 1 µm 230 x 1 µm 300 x 1 µm 400 x 1 µm 600 x 1 µm Maximum peak 7 A 15 A 22 A 30 A 40 A 60 A forward current ifm ith Typical.5 A 1.0 A 1.5 A 2.5 A 2.5 A 3.0 A Series Ω Ω Ω Ω Ω Ω resistance (RDS) Preferred S S S S S S package Package C,F,R,U,Y C,F,R,U,Y C,F,R,U,Y C,F,R,U,Y C,F,R,Y C,F,R,Y options Table 4. Stacked arrays Parameters PGAS3S06H PGAS3S09H PGAS3S12H PGAS4S12H PGAS4S16H PO at ifm Min 31.0 W 46.0 W 62.0 W 82.0 W W Typ 36.0 W 53.0 W 70.5 W 94.0 W W Number of elements Emitting area 150 x 225 µm 230 x 225 µm 300 x 225 µm 300 x 340 µm 400 x 340 µm Maximum peak 15 A 22 A 30 A 30 A 40 A forward current ifm ith Typical 1.0 A 1.5 A 2.5 A 2.5 A 2.5 A Series Ω Ω Ω Ω Ω resistance (RDS) Preferred S S S S S package Package C,F,R,U,Y C,F,R,U,Y C,F,R,U,Y C,F,R,U,Y F,R,Y options 4

5 Warning - Personal safety hazard Laser radiation Under operation, these devices produce invisible electromagnetic radiation that may be harmful to the human eye. To ensure that these laser components meet the requirements of Class IIIb laser products, they must not be operated outside their maximum ratings. Power supplies used with these components must be such that the maximum peak forward current cannot be exceeded. It is feasible to operate the diodes within Class I laser operation, but it is the responsibility of the user incorporating a laser into a system to certify the Class of use and ensure that it meets the requirements of the DHHS or appropriate authority. Further details may be obtained in the Publication FDA from: US Department of Health and Human Services Food and Drug Administration Center for Devices and Radiological Health 1390 Picard Drive Rockville, MD U.S.A. PerkinElmer Optoelectronics has used the data in the above document to calculate Accessible Emission Limits in terms of radiation power output and plotted them against pulse width for 850 nm and 150 nm lasers. Ask for Technical Report A Comparison of the Accessible Emission Limits (AEL s) for Laser Radiation at 850 nm and 1500 nm. Package C Package F Package C: Pin out: Case (-), Pin (+), Inductance 12 nh Package F: Pin out: Case (-), Pin (+), Inductance 11 nh 5

6 Package R Package S Package U Package Y 6

7 Figure 1. Peak radiant intensity vs temperature Figure 2. Total peak radiant intensity vs peak drive current Figure 3. Peak wavelength vs temperature for single elements Figure 4. Typical spectral width vs temperature Figure 5. Radiant intensity vs F number Figure 6. Radiant intensity vs half angle 7

8 Figure 7. Radiant intensity vs pulse width for safe operation Figure 8. Spectral plot distribution Figure 9. Far field pattern parallel to junction plane Figure 10. Far field pattern perpendicular to junction plane Your Partner of Choice With a broad customer base in all major markets, built on ninety years of solid trust and cooperation with our customers, PerkinElmer is recognized as a reliable partner that delivers high quantity, customized, and superior "one-stop" solutions. Our products - from single photocells to complex x-ray inspection systems - meet the highest quality and environmental standards. Our worldwide Centers of Excellence, along with our Customer and Technical Support teams, always work with you to find the best solutions for your specific needs. PerkinElmer Optoelectronics PerkinElmer Optoelectronics is a global technology leader providing marketdriven, integrated solutions for a wide range of applications, which leverage our lighting, sensors, and imaging expertise. Our technologies, services and support are fueling the medical, genomic and digital revolutions by enhancing our customers' productivity, optimizing performance, and accelerating time to market. So contact us and put PerkinElmer's expertise to work in your demanding applications. We will show how our innovations will help you deliver the perfect product. RoHS Compliance This series of laser diodes are designed and built to be fully compliant with the European Union Directive 2002/95EEC Restriction of the use of certain Hazardous Substances in Electrical and Electronic equipment. North America Customer Support Hub Dumberry Road Vaudreuil-Dorion, Québec Canada J7V 8P7 Telephone: (+1) , (+1) (toll-free) Fax: (+1) opto@perkinelmer.com European Headquarters Wenzel-Jaksch-Str Wiesbaden, Germany Telephone: (+49) Fax: (+49) opto.europe@perkinelmer.com Asia Customer Support Hub 47 Ayer Rajah Crescent #06-12 Singapore Telephone: (+65) Fax: (+65) opto.asia@perkinelmer.com For a complete listing of our global offices, visit PerkinElmer, Inc. All rights reserved. The PerkinElmer logo and design are registered trademarks of PerkinElmer, Inc. All other trademarks not owned by PerkinElmer, Inc. or its subsidiaries that are depicted herein are the property of their respective owners. PerkinElmer reserves the right to change this document at any time without notice and disclaims liability for editorial, pictorial or typographical errors _02 DTS0108