product catalog Table of Contents:

Transcription

1 product catalog Table of Contents: THz Lenses...pg 2 Free Standing Wire Grid Polarizers...pg 4 MID-IR Polarizers...pg 6 Golay Cells...pg 7 Pyroelectric Detectors...pg 9 Semiconductor Detectors...pg 10 Magnetic System MS pg 11 Power Supply VR-2M...pg 12 Power Supply VR-3M...pg 13 Power Supply VR-6M...pg 14 Power Supply VR-6MU...pg 15 THz Generators...pg 16 Compact THz Generators...pg 18 Scanning Spectrometers...pg 19 THz Imaging System...pg 20 THz Spectrometers...pg 22 Software Package Epsilon...pg 24

2 THz lenses Polished Picarin Lenses focus THz and visible light Picarin is highly transparent in THz and visible spectral ranges (see transmission spectra on the next page). Refractive index of Picarin is almost the same for THz (n=1.56) and visible light (n=1.55). Model Lens type External diameter/ clear aperture Focal length PPL mm-AS Plano-convex, aspheric 1.5 / 30 mm 50 mm PPL mm-AS Plano-convex, aspheric 1.5 / 30 mm 100 mm PPL-2-50mm Plano-convex, spherical 2 / 45 mm 50 mm PPL-2-100mm Plano-convex, spherical 2 / 45 mm 100 mm PPL-2-180mm Plano-convex, spherical 2 / 45 mm 180 mm PPL-1.5 -XXXmm Plano-convex, spherical 1.5 / 30 mm Any > 30 mm PPL-2 -XXXmm Plano-convex, spherical 2 / 45 mm Any > 50 mm Polyethylene Lenses Offer the best performance at frequencies below 1 THz and above 7 THz (see transmission spectra on the next page). Polyethylene is not transparent in visible and near-ir spectral ranges, so that the lenses can be used to block light. Model Lens type Holder diameter/ clear aperture Focal length PL-2-60mm Bi-convex, spherical 2.75 / 2 60 mm PL-2-100mm Bi-convex, spherical 2.75 / mm pg 2

3 THz lenses Transmission spectra of Picarin and Polyethylene in THz spectral range Picarin (2 mm slab) Polyethylene (2 mm slab) Transmission (%) Frequency (THz) Transmission spectrum of Picarin in the visible spectral range Picarin (3 mm slab) 60 Transmission (%) WAVELENGTH (nm) pg 3

4 free standing wire grid polarizers Product description: These polarizers are made of 10 μm or 15 μm tungsten wire wound on a circular frame with spacing ranging from 25 μm to 500 μm. Operating frequency range-up to 3 THz (see transmission and reflection spectra below) Polarizer Model Wire diameter/ Wire spacing (μm) G25-S 10 / / 50 G30-S 10 / / 50 G30-L 10 / / 98 G40L 10/40 88 / 98 G45-S 10 / / 50 G45-L 10 / / 98 G60-S 15 / / 50 G60-L 15 / / 98 G80-S 15 / / 50 G80-L 15 / / 98 G100-S 15 / / 50 G100-L 15 / / 98 G130-S 15 / / 50 G130-L 15 / / 98 G200-S 15 / / 50 G200-L 15 / / 98 G300-S 15 / / 50 G300-L 15 / / 98 G500-S 15 / / 50 G500-L 15 / / 98 Clear aperture / External diameter (mm) Wire Grid Polarizer Holders: We carry 2 types of rotating holders for the wire grid polarizers. Model RH1 is designed for 98 mm diameter polarizers, and enables a 360 rotation. Model RH2 is designed for 98 mm diameter polarizers, and enables 2-axis adjustments and 360 rotation. pg 4

5 FREE STANDING WIRE GRID POLARIZERS Transmission spectra of radiation polarized perpendicular and parallel to the wires Transmission E wires G200 G100 G30 G Frequency (GHz) E wires 10-1 G G500 G45 G G300 G30 G200 G G130 G G80 Transmission Frequency (GHz) Reflection pg 5

6 mid-ir polarizers Product description: MIP polarizers comprise of a metal wire grid manufactured on a thin polyethylene film. High wire density (1200 wires/mm) and high transparency of a 60 μm-thick polyethylene substrate extended operating spectral range of these polarizers to 4000 cm -1 (2.5 μm; 120 THz). Transmission spectra of radiation polarized perpendicular and parallel to the wires: 1 IR polarizer. Substrate -polyethylene EI wires 0,1 Transm. 0,01 EII Wires 1E ν, cm -1 Ordering information: Model Clear aperture diameter (mm) External diameter (mm) Number of wires per millimeter MIR MIR sustrate thickness (μm) pg 6

7 golay cells Product description: Golay Cell is an opto-acoustic detector designed for operation in the spectral range THz. It is equipped with a 6 mm diameter polyethylene input window that provides for high transparency at frequencies up to 20 THz. Black polyethylene input windows are available as an option to cut off optical radiation. Golay Cell includes a build-in preamplifier. Operation of a Golay Cell requires a three-unit power supply delivering the following: +15 V, -15 V and 32 ma. Such a power supply is also available as an option Performance of Golay Cells is detrimentally affected by mechanical vibrations. Addressing this problem, our Golay Cells are mounted on proprietary vibration-isolating bases. Technical Specifications: Parameter Responsivity at 12.5 Hz modulation, V/W Value v/w Sensitivity at 12.5 Hz modulation, W/Hz 1/ v/hz 1/2 Maximum modulation frequency Dynamic range 50 Hz 10 nw μw Rise time, ms 25 Maximum output voltage, V 3.0 Input window diameter, mm 6 Dimensions, mm 135 x 115 x 120 Operating Conditions: Parameter Value Value Temperature, o C +15 to +25 Pressure, Pa 8.4 x 10 4 to 10.7 x 10 4 Humidity, % Application Notes: The Golay Cell can be used to detect both CW and pulsed THz radiation. However, due to a 25 ms response time, only average power can be measured for short pulse/high repetition rate THz sources. Spectral response is lowered by transmission charactersistics of the input window. pg 7

8 golay cells Golay Cell Responsivity Spectrum Diamond Input Window Polyethylene Input Window Responsivity (V/W) Frequency (THz) Notes: Golay Cell responsivity was measured for a unit with 2 mm thick polyethylene input window at modulation frequency of 12.5 Hz. pg 8

9 pyroelectric detectors Product description: The pyroelectric detector based on LiTa03 crystal, is designed for registration of modulated electromagnetic radiation in the millimeter and sub-millimeter wavelength range. At square wave modulation of radiation, the saw-tooth signal voltage from the detector is proportional to the intensity of radiation. A black filter is mounted on the detector input to prevent parasitic illumination in visible and infrared regions. The detector is equipped with a standard BNC connector. Technical Specifications: Parameter Value Operating spectral range, THz Responsitivity V/W 1000 Optimal modulation frequency, Hz 5-30 Noise level, mv 1.0 Power supply voltage (2 AA batteries), V 2 x 1.5 Power supply current, mv 0.14 Operating battery lifetime, hours > 10,000 Dimensions, mm 135 x 40 x 30 Application Notes: Pyroelectric detectors operate over a wide spectral range of THz (with a black filter) or up to near-ir (without the filter). These detectors provide for lower responsivity than Golay Cells, but have a faster response time. pg 9

10 semiconductor detectors Product description: Semiconductor THz detectors based on GaAs Schottky diode are designed to operate in spectral range THz. Planar design of diodes enable very high speed operation - up to 20 GHz. We offer three different models: SD-200, SD-400, SD-750. However, most of our semiconductor THz detectors are custom made. Technical specifications: Parameter / Model sd-200 SD-400 sd-750 Operating frequency range, GHz Responsivity V/W Sensitivity W/Hz 1/2 <8x10-11 <2x10-10 <1.6x10-9 Maximum modulation frequency 20 GHz 20 GHz 20 GHz Dynamic range 80 pw - 1 μw 640pW - 1 μw Input waveguide WR-3 WR x0.25 Dimensions, mm 60x20x20 60x20x20 28x19x19 Application notes: Compared to Golay Cells and pyroelectric detectors, semiconductor THz detectors offer lower sensitivity and limited operating frequency range. The main advantage of semiconductor detectors is high speed - up to 20 GHz. pg 10

11 magnetic system ms-1.2 Product description: The MS-1.2 magnetic system includes a 1.2 Tesla permanent magnet designed to house a high-frequency BWO operating in the spectral range of THz. The system is equipped with a 2- axis mechanical rotation stage for centering BWO in the magnetic field. The system also has inputs for BWO electrical connections and a water cooling system. Mechanical specifications: Height: 300 mm; Width: 300 mm; Depth: 300 mm; Weight: 42 kg. Additional views: pluggable water lines pluggable electrical connector 2-axis mechanical rotation stage bwo output high voltage connector Front View Top view water back view (open front panel) (open top panel) in/out (open back panel) pg 11

12 power supply vr-2m Product description: VR-2M is designed to power tunable monochromatic quasi-optical sources of millimeter and sub-millimeter wavelength radiation based on Backward-Wave Oscillators (BWOs) operating in the frequency range GHz VR-2M consists of three modules: cathode power supply, grid power supply and heater power supply unit. All the voltages are highly regulated, insuring stable BWO operation with very low level of incidental modulation on the output power. Cathode power supply: - Output: V at load current mA. - Polarity: negative (relative to a grounded BWO anode). - Ripple and noise: less than 10mV. - Line regulation (5% voltage change) 0.001%. - Load regulation (100% load change) 0.001%. - Output Voltage Slew rate: 1 V/ s - Modulation: triangle form 2.5kHz, 0-50 V (peak-to-peak). - Overload and short circuit protection. - Computer control via RS-232 interface (IEEE-488 (GPIB) - optional) Grid power supply: - Voltage DC 200V - Maximum current 7mA - Automatically switched off, if the cathode voltage is less than 200V Heater power supply: - Maximum DC current is 2.75A, regulated. - Maximum voltage is 1.4V. - Automatically switched off, if the cathode voltage is less than 200V Input power requirements: - Voltage AC: 110 V or 220 V +/-5% - Power Consumption: 120 W. Mechanical specifications: Height: 150 mm; Width: 380 mm; Depth: 380 mm; Weight: 15 kg. pg 12

13 power supply vr-3m Product description: VR-3M is designed to power tunable monochromatic quasi-optical sources of millimeter and sub-millimeter wavelength radiation based on Backward-Wave Oscillators (BWOs) operating in the frequency range GHz. VR-3M consists of three modules: cathode power supply, grid power supply and heater power supply unit. All the voltages are highly regulated, insuring stable BWO operation with very low level of incidental modulation on the output power. Cathode power supply: - Output: V at load current mA. - Polarity: negative (relative to a grounded BWO anode). - Ripple and noise: less than 10mV. - Line regulation (5% voltage change) 0.001%. - Load regulation (100% load change) 0.001%. - Output Voltage Slew rate: 1 V/ s - Modulation: triangle form 2.5kHz, 0-50 V (peak-to-peak). - Overload and short circuit protection. - Computer control via RS-232 interface (IEEE-488 (GPIB) - optional) Grid power supply: - Voltage DC 200V - Maximum current 7mA - Automatically switched off, if the cathode voltage is less than 200V Heater power supply: - Maximum DC current is 2.75A, regulated. - Maximum voltage is 1.4V. - Automatically switched off, if the cathode voltage is less than 200V Input power requirements: - Voltage AC: 110 V or 220 V +/-5% - Power Consumption: 120 W. Mechanical specifications: Height: 150 mm; Width: 380 mm; Depth: 380 mm; Weight: 15 kg. pg 13

14 power supply vr-6m Product description: VR-6M is designed to power tunable monochromatic quasioptical sources of terahertz radiation based on Backward-Wave Oscillators (BWOs) operating in the frequency range THz. VR-6M consists of two modules: cathode power supply and heater power supply unit. All the voltages are highly regulated, insuring stable BWO operation with very low level of incidental modulation on the output power. An optional software package and digital-toanalog converter (DAC-16) enable computer control of the system. Cathode power supply: - Output voltage: V DC - Output current at the external load: mA DC - Output voltage polarity: negative relative to the grounded BWO- anode. - Output voltage ripple and noise: not more than 40mV (p-p). - Output voltage change (at 5% line voltage change): 0.002%. - Output voltage change (at 100% load change): 0.002%. - Manual voltage control: Coarse: V via 10-turn potentiometer, Fine: 3V via 1-turn potentiometer. - Automatic voltage control: via the external voltage (+10-10)V using Digital-to-Analog Converter (DAC-16). - Output voltage slew rate: 1 V/ s - Internal modulation: triangle form 2.5kHz, V(p-p). - Metering: 6kV-voltage panel meter, 60mA-current panel meter. - Protection: overload and short circuit protection. Heater power supply: - Output current: A AC, 360Hz (sinusoidal). - Output voltage: 0 8V AC (eff.). - Manual current control: via 3-digit tumble-wheel switch. - Automatic current loading/unloading system. - Metering: 3A-current panel meter. Input power requirements: - Input AC Voltage: 110 V or 220 V +/-5% - Power consumption 500 W (typical). Mechanical specifications: Height: 250 mm; Width: 500 mm; Depth: 500 mm; Weight: 29 kg. pg 14

15 power supply vr-6mu Product description: VR-6U is designed to power tunable monochromatic quasioptical sources of terahertz radiation based on Backward-Wave Oscillators (BWOs) operating in the frequency range THz. VR-6MU consists of three modules: cathode power supply, grid power supply and heater power supply unit. All the voltages are highly regulated, insuring stable BWO operation with very low level of incidental modulation on the output power. An optional software package and digital-to-analog converter (DAC-16) enable computer control of the system. Cathode power supply: - Output voltage: V DC - Output current at the external load: mA DC - Output voltage polarity: negative relative to the grounded BWO- anode. - Output voltage ripple and noise: not more than 40mV (p-p). - Output voltage change (at 5% line voltage change): 0.002%. - Output voltage change (at 100% load change): 0.002%. - Manual voltage control: Coarse: V via 10-turn potentiometer, Fine: 3V via 1-turn potentiometer. - Automatic voltage control: via the external voltage (+10-10)V using Digital-to-Analog Converter (DAC-16). - Output voltage slew rate: 1 V/ s - Internal modulation: triangle form 2.5kHz, V(p-p). - Metering: 6kV-voltage panel meter, 60mA-current panel meter. - Protection: overload and short circuit protection. Grid power supply: - Voltage DC: 200V - Maximum current: 7mA - Automatically switched off, if the cathode voltage is less than 200V Heater power supply: - Output current: A AC, 360Hz (sinusoidal). - Output voltage: 0 8V AC (eff.). - Manual current control: via 3-digit tumble-wheel switch. - Automatic current loading/unloading system. - Metering: 3A-current panel meter. Input power requirements: - Input AC Voltage: 110 V or 220 V +/-5% - Power consumption 500 W (typical). Mechanical specifications: Height: 250 mm; Width: 500 mm; Depth: 500 mm; Weight: 29 kg. pg 15

16 thz generators Backward Wave Oscillators (BWOs): High power: mw Narrow spectral line-width: 1-10 MHz Wide spectral range: THz BWOs are electro-vacuum diodes, where THz emission is generated by electrons decelerating in a periodic electric field. BWO emission wavelength is tuned by a voltage applied to one of the electrodes (cathode). Tables below show tuning ranges for a number of different BWOs. BWO model # QS-200 ov85 QS-260 ov84 QS-300 ov83 QS-400 ov81 Frequency range, THz Output power, mw Cathode Voltage, kv BWO model # QS-500 ov80 QS-700 ov32 QS-1000 ov30 QS-1500 ov24 Frequency range, GHz Output power, mw Cathode Voltage, kv BWO model # QS-2 ov86 QS-3 ov71 QS-4 ov70 QS-6 ov69 Frequency range, GHz Output power, mw Cathode Voltage, kv Computer Control of THz Sources Digital to Analog Converter (DAC-16) enables computer control of high voltage power supplies VR-2M, VR-3M, VR-6M, VR-6MU via RS-232, GPIB or USB interfaces THz Generator software package provides for a windows based interface to control THz sources via DAC-16 and high voltage power supplies. pg 16

17 THz generators BWO Power Supplies and Magnets Operation of BWO-based THz sources requires a high voltage power supply (e.g. VR-6MU) and a magnetic system (e.g. MS-1.2) that houses a BWO tube. High Voltage Power Supplies: VR-series power supplies provide for highly stabilized cathode voltage ranging from 0 to 6000 V, as well as BWO grid and heater voltages. The software package (THz generator) and digital-to-analog converter (DAC-16) enable computer control of the power supplies via RS-232, GPIB or USB interfaces. Model # Max Voltage Application VR-2M 2000 V Very Low Frequency BWOs ( 100GHz) VR-3M 3000 V Low Frequency BWOs ( 180 GHz) VR-6M 6000 V High Frequency BWOs ( 180 GHz) VR-6MU 6000 V All types of BWOs Focusing Magnetic System MS-1.2: MS-1.2 magnetic system includes a 1.2 Tesla permanent magnet designed to house high-frequency BWOs operating in the spectral range THz. The system is equipped with a 3-axis mechanical translation stage for centering BWO in the magnetic field. The system also has inputs for BWO electrical connections and water cooling system. BWO cooling system: BWOs operating at frequencies above 180 GHz require water cooling. While BWO dissipates only 300 W of heat, the cooling system has to provide for at least 40 psi of water pressure, due to very narrow tubing on BWO. We recommend a Lytron MSC cooling systems, which can be also purchased through Microtech Instruments. pg 17

18 compact thz generators Product description: Product specifications: These generators are based on a QS2 Backward Wave Oscillator (BWO) combined with frequency multipliers. While QS2 is only tunable in range GHz, combination of QS2 with frequency multipliers extends the operating spectral range to 1.6 THz. The frequency multipliers are very compact (1 x0.5 x0.5 ) solidstate electronic devices that are attached directly on the QS2 output waveguide. Operation of frequency multipliers does not require any drivers. Power conversion efficiency of the multipliers varies from 0.1 to 20 percent, depending on the frequency range. Starting with 100 mw of power generated by QS2, output power of the multiplied source ranges from a few μw to 20 mw. Model tuning range output power QS GHz mw QS2-D GHz 1-10 mw QS2-T GHz mw QS2-DT GHz μw QS2-TT GHz 1-5 μw Frequency multiplier: Computer Control of THz Sources: While QS2-D and QS2-T are comparable in power and tuning range to QS-1500, QS-1000, QS-700. QS2-DT is covering the spectral range of QS-500, QS-400 and QS-300 combined at the expense of lower power. QS2-TT exceeds the tuning range of QS-260 and QS-200 combined, extending operation of BWO-based sources to 1.6 THz. However, the output power falls significantly at higher frequencies. Apart from the wide tuning range, advantages of multiplied BWO sources include compact size, light weight, lower operating voltages and no water cooling, making them attractive for applications requiring portability. Digital to Analog Converter (DAC-16) enables computer control of the high voltage power supply VR-3M via RS-232, GPIB or USB interfaces THz Generator software package provides for a windows based interface to control THz sources via DAC-16 and high voltage power supplies. pg 18

19 scanning spectrometers Spectral Range THz Spectral Resolution Dynamic Range 30 GHz - 1.5THz 1-10 MHz 10 6 THz spectrometer is a user friendly, computer controlled system employed in leading research institutions worldwide. 100 o o o p p Transmission (%) 50 p o p p o o o Frequency (cm -1 ) Transmission cm pg 19

20 THZ imaging system Computer controlled THz imaging system takes advantage of high power of BWO-based THz generators and high sensitivity of Golay Cell. The system designed to operate in the range 100 GHz 1.42 THz. It provides for scanning range of 2-4 cm with spatial resolution up to 100 μm. pg 20

21 THZ imaging system Test sample: open aperture Operating Principle Detector Input window Two dimensional THz images are obtained by scanning the THz detector/pin-hole assembly THz Radiation Scanned region Pin-hole THz image obtained using 300 GHz radiation. Spatial distribution of intensity (up)and its plane cut (down).scanned region 15 mm, step 100 um. X (mm) Y (mm) X (mm) pg 21

22 THZ SPECTROMETERS THz spectrometers offered by Microtech Instruments enable high-resolution spectroscopic measurements in the spectral range from 30 GHz to 1.25 THz. These systems employ frequency tunable Backward Wave Oscillators (BWOs) as sources of THz radiation and Golay Cells as detectors. Key features include: Wide spectral range: 30 GHz THz High spectral resolution: 1-10 MHz Wide Dynamic Range: 10 5 Transmission measurement is the best method for characterization of highly transparent materials. In particular, transmission spectra of plane parallel plates exhibit a periodic transmission pattern caused by interference (Fabry-Perot etalon fringes). Real and imaginary parts of the dielectric constant can be determined from these measurements, as the period and amplitude of the etalon fringes depend on the material refractive index and absorption, respectively. pg 22

23 THZ SPECTROMETERS Characterization of semi-transparent materials requires a THz Mach-Zehnder interferometer (shown below), since no etalon fringes can be observed in the transmission spectra of such materials. The Mach-Zehnder setup enables measurements of a phase shift induced by the sample as a function of frequency. Combining this data with transmission spectrum, real and imaginary parts of the dielectric constant can be calculated. The transmission, Mach-Zehnder and reflection spectrometers are supported by EPSILON software, enabling automated data acquisition and analysis. One spectral scan takes min for each of the BWOs employed in the system. pg 23

24 Software Package EPSILON EPSILON offers a Windows-based interface for THz spectrometer operation and data analysis. It enables the following functions: Control of THz spectrometer equipment, including sources, detector and data acquisition unit. Data acquisition, analysis and storage of measured spectra THz source calibration using a set of standard samples and/or Fabry-Perot interferometer. Storage of calibration parameters. The program is compatible with Windows-95/98/ NT/2000/XP. Pricing information is available on request at sales@mtinstruments.com 132 East Broadway, Suite 810, Eugene, OR 97401, USA Phone: Fax: pg 24 MICROTECH instruments, inc.