Judson Technologies J12 SERIES INAS DETECTORS PB 220 October 2000 Operating Instructions Typical J12 Series Operating Circuit RF > 10x RD IS - Vo = IS * RF + Detector Ios Preamp Selection vs Shunt Selection Impedance Recommended Detector Shunt Op Amp Impedance (ohms) LT 1028, 1 to 500 Discrete FET OP27, 500 to 2000 Discrete FET OPA111, LF356, 2000 Discrete FET Detectivity vs Wavelength for J12 Series 10 12 J12T 1011 E4 ( J12T -85 E3 ( PA-6, PA-9 PA-7, PA-9 C) 100 C) -65 80 C) -40 E2 ( J12T C) 1010 0 1 (-2 E J12T 109 J12 C) (22 60 R bias (~10Kohm) 2 3 Wavelength (m) 4 Figure 2.0 Capacitor .01 to .1 F (ceramic) Coax Cable 40 to Oscilloscope V 20 0 1 Figure 1.0 PA-5, PA-9 High Speed Operating Circuit 108 Vos Judson Preamp Table I Relative Capacitance (%) Frequency Response The feedback resistance RF, combined with the detector capacitance and dynamic impedance, determines the frequency response of the system. Capacitance and impedance values are provided on the data sheet supplied with each detector. Recommended Preamplifiers The PA5, PA6 and PA7 have adjustable gain and low noise. Preamplifiers should be picked by the detector shunt impedance at the optimal operating temperature for a particular application (Table 1). The PA9 should be used where high frequency response and low noise are required. The PA9 may not be suitable for DC applications due to its high input offset voltage. D* (, 1KHz, 1Hz) (cmHz/W) Operating Circuit The recommended operating circuit for most applications is an operational amplifier in a negativefeedback transimpedance configuration. The feedback circuit converts the detector output current to a voltage, while the op-amp maintains the detector near zero-volt bias for lowest noise. (Figure 1.0). Because RD varies significantly with temperature, selection of the proper op-amp will depend on the detector operating temperature as well as the desired bandwidth. The feedback resistor RF should be at least 10x greater than RD for best signal-to-noise ratio. Judson has preamplifiers for optimum performance with each detector type. For high frequency applications, the detector may be reverse biased and terminated into a low impedance load. Maximum reverse bias is 1 volt. (See Figure 3.0). bias +5V to +10V J12 Series photodiode R L (50ohm 1Kohm) 2 4 6 8 Reverse Bias Voltage VR (Volts) Figure 3.0 10 J12 SERIES INAS DETECTORS Operating Instructions Test Conditions All Judson detectors undergo stringent quality control testing before shipment. A test setup (Figure 4.0) is used to check J12 Series detectors for responsivity (R) and detectivity (D*). Aperture Chopper Detector/ Heat Sink .01 V Preamp HSA2 Assembly Wave Analyzer Digital Multimeter TC5 Temp. Controller Figure 4.0 dI -.01 V RD = dV dI dV RF 500K Blackbody Scope Detector Shunt Impedance Effective dynamic impedance of the detector at operating temperature, measured at 0 volts bias (Figure 5.0). Figure 5.0 Blackbody Responsivity (RBB) Defined as the current produced by a detector in response to the radiant power on the detector (amps/watt) (Figure 6.0). For the test setup, RBB is equal to Vout/(HBBADGain) where HBB is the blackbody irradiance in watts/cm2, AD is the area of the detector in cm2, Vout is the rms signal voltage at the output of the preamplifier in volts, and Gain is the gain of the preamplifier in volts/amp. Detector Response to Incoming Photons A copy of the test data is provided with each detector and includes the following test condition information: I Photon Chopping Frequency Frequency of chopper for modulating the blackbody source signal. Blackbody Temperature Absolute temperature in K of the blackbody source used for response test. Background Temperature Room temperature in K. Detector Temperature Operating temperature of the detector during the test. V Io dark Io light I light x R F = Vout Figure 6.0 Peak Responsivity (R) Responsivity in amps/watt at the wavelength of peak response. Related to blackbody responsivity by R= RBBG, where the constant G is the ratio of total blackbody power to the power "utilized" by the detector. For InSb detectors without filters, G 5.5 and is determined as follows: G-1 = 1 N(,TBB) R() d WBB R(p) where N(,TBB) is the irradiance at in w/cm2/ and WBB is the total blackbody irradiance in w/cm2. J12TE Detector Response vs Wavelength & Temperature 1.50 1.25 Responsivity (A/W) Flux Density (H) Actual rms total power in watts/cm2 irradiating the detector surface. Equal to FT4BB/As/d2 where F is the rms constant of the chopper ( 0.36), is the StefanBoltzman constant, TBB is the blackbody temperature, As is the aperture area and d is the source-to-detector distance. 1.00 0.75 22C -20C -40C -65C -85C 0.50 0.25 0.00 2.0 2.5 Figure 7.0 3.0 3.5 Wavelength (m) 4.0 J12 SERIES INAS DETECTORS Operating Instructions Calculating Detector Response Uniformity For a J12-5AP-R02M: R D - RS 10-6 4 = = = 40% response at center RD 10 10 Detector Equivalent Circuit Iph R bias IS RS L O A D V bias -0.1V CD VD RD For a J12-5SP-R02M: R D - RS 100-6 94 = = = 94% response at center RD 100 100 Iph = Current generated by incident photons VD = Actual voltage across diode junction CD = Detector junction capacitance RD = Detector shunt resistance Rs = Detector series resistance Is = Output signal current * High ratio of Detector Shunt Impedance to series resistance = high uniformity. Output signal current from detector Is is defined as: ( ) Isignal = Iphoton Detector shunt () - Detector series () Detector shunt () For J12-5AP-R02M Isignal = 1.25A/W = .5A/W (10-6 10 ) J12 Series Detector Noise * Noise due to shunt impedance or noise current Johnson (thermal) noise int = For J12TE2-8B6-R02M 200-6 Isignal = 1.25A/W = 1.21A/W 200 ( ) "Light Spot" From Source where Rsh = detector shunt resistance or feedback resistance whichever is lower. K = Boltzmans Constant (1.38 x 10-23 joules/K) T = Operating Temperature (K) f = Noise Equivalent Bandwidth (Hertz) Rsh = Shunt Resistance (ohms) Direction of Spot Scan Across Surface * Noise due to Capacitance at a frequency For a photovoltaic detector junction capacitance can dominate noise at high frequency. Detector Ring Contact -1 -.5 0 +.5 +1 mm Active Area Position in = (Preamp voltage noise floor) (2fCD) Series resistance is approx. 0 at contact. Total series resistance is approx. 5 - 10, approx. 6 nominal. Therefore, response uniformity is a fucntion of the voltage divider in the equivalent circuit RD and RS. -40C 0C Contact Contact 100% Relative Response 4KTf Rsh 50% 22C Active Area 0 -1 -.5 0 +1 +.5 Active Area Position (mm) J12 SERIES INAS DETECTORS Shunt Resistance vs Temperature 1M 10K -50 TD I vs e tag 2.0mm m 3-S 0.25m m -30 e ag St 2- -10 2.0m m m 5 0.2 ge 1-Sta 2.0mm V vs I Cooler 10 3 2 1 Hot side = 27C Cooler Voltage V (Volts) 0.25mm 0.2 0.4 0.6 0.8 1.0 1.2 Cooler Current I (Amps) 0 Figure 8.0 1K -60 Co ole -40 Co ole -20 0 20 rC rC urr urr en en t= t= 0.5 Heat Sink for 8B6, 66S pkgs 1A mp Am p 0.25 1" dia 40 -20 0 20 40 60 80 100 Heat Sink Temperature TH (C) 250m dia. Figure 9.0 100 1M 10 1mm dia. R 0 -80 S +R D 2mm dia. -60 -40 -20 0 +20 +40 Detector Temperature (C) Thermoelectric Cooler Operation Figure 8.0 shows typical power requirements for the TE1, TE2 and TE3 coolers. The built-in thermistor can be used to monitor or control the temperature. Figure 10.0 shows typical thermistor resistance vs. temperature values. Sensitivity, cutoff wavelength and response uniformity are all functions of temperature. Detector temperature should be optimized for a particular application. Thermistor Resistance (K) Shunt Resistance RD () 100K -70 30 Detector Temperature TD (C) Temperature Effects Cooling an InAs photodiode reduces noise and improves detectivity. Cooling also increases shunt resistance RD allowing more of the photocurrent Iph to reach the contact ring. The result is an increase in the diode response. For high-power applications such as pulsed laser detection, cooling is generally not necessary. For sensitive, low-power applications such as temperature measurements, the InAs detector should be cooled or at least temperature-stabilized. Stabilizing the temperature near 22C room temperature will not improve performance, but will prevent changes in detector response due to ambient temperature drift. Cold Side Temperature TD (C) Operating Instructions 100K 10K 1K 100 -80 -60 -40 -20 0 +20 +40 Detector Temperature (C) Detector Temperature 22C -40C -65C Thermistor Value (K) Min. Typ. Max. 1.3 15.0 30.0 40.0 60.0 85.0 100.0 Figure 10.0 J12 SERIES INAS DETECTORS Operating Instructions Active Model Number Part Number Size (dia.) Operating Temperature Cutoff Wavelength @ co (50%) (mm) (m) J12 Series Room Temperature InAs 420002 0.25 J12-18C-R250U 420003 1.00 22C 3.60 J12-18C-R01M 420011 2.00 J12-5AP-R02M J12TE1 Series One-Stage Thermoelectrically Cooled InAs 420088 0.25 J12TE1-37S-R250U 420061 1.00 -20C 3.50 J12TE1-37S-R01M 420065 2.00 J12TE1-37S-R02M J12TE2 Series Two-Stage Thermoelectrically Cooled InAs 420083 0.25 J12TE2-66D-R250U 420041 1.00 -40C 3.45 J12TE2-66D-R01M 420089 2.00 J12TE2-66D-R02M J12TE3 Series Three-Stage Thermoelectrically Cooled InAs 420081 0.25 J12TE3-66D-R250U 420056 1.00 J12TE3-66D-R01M -65C 3.40 420063 1.50 J12TE3-66D-R1.5M 420098 2.00 J12TE3-66D-R02M J12TE4 Series Four-Stage Thermoelectrically Cooled InAs 0.25 J12TE4-3CN-R250U 420093 1.00 -85C 3.30 J12TE4-3CN-R01M 2.00 J12TE4-3CN-R02M-B * LD2 Shunt Resistance RD @ VR = 10mV Responsivity @ p Maximum NEP @ peak and 1KHz Minimum D* @ peak and 1KHz (Jones) Capacitance (A/W) Min. (ohms) Typ. (ohms) (pW/Hz ) (cmHz W ) (pF) 1.5 1.0 0.8 200 15 5 300 25 10 6.0 33 71 3.7E9 2.7E9 2.5E9 50 400 1600 LD2 1.5 1.5 1.25 2000 200 50 3000 300 90 1.8 5.6 13 1.3E10 1.6E10 1.3E10 50 400 1600 HS1, CM21 1.5 12K 1.2K 300 24K 2.4K 500 .69 2.2 4.4 3.2E10 4.1E10 4.1E10 50 400 1600 HS Amp, HS1, CM21, CM Amp 1.5 160K 10K 5K 2.5K 320K 20K 10K 5K .18 .71 1.0 1.4 1.2E11 1.2E11 1.3E11 1.2E11 50 400 800 1600 HS Amp, HS1, CM21, CM Amp 1.5 400K 25K 6.5K 800K 50K 13K .11 .43 .84 2.1E11 2.1E11 2.1E11 50 400 1600 HS Amp, HS1, CM21, CM Amp * 5AP 1/2 1/2 -1 * 18C .07 to detector plane .326 .240 .10 to detector plane .187 .110 .200 .190 (+) Case(-) (+) Case(-) .50 (nom) * 8B6 * 66S Sapphire Window Detector Plane Dim. "A" 0.32 .50 (nom) .10 dia pin circle .20 dia pin circle * 37S Optional Packages and Accessories CD @ VR = 0V 0.28 DIMENSION "A" J12TE2-66S 0.12" J12TE3-66S 0.07" Sapphire 0.55 dia. Window 0.20 0.435 0.5 0.06 Background Pins Omitted Side View .425 dia. Pin Circle Background Pins Omitted 0.50 Side View Thermistor pins 6 pins on .200" bolt circle Thermistor 0.76 .147 dia 2 holes Detector(-) Detector(+) 0.56 1.24 0.96 0.37 Cooler(+) Cooler(-) Detector(-) Detector(+) Cooler (+) 0.690 Bottom View Bottom View Cooler (-) J12 SERIES INAS DETECTORS Operating Instructions Temperature Controllers The Judson Model TC5 power supply and temperature controller provides convenient cooler operation at a range of fixed temperatures. The built-in thermistor is used to stabilize the detector temperature. To operate without automatic temperature control, use a 2.5V power supply. Beginning with a fixed voltage and low current, gradually increase the current as the detector cools. The thermistor can be used to monitor the detector temperature if desired. Heat Sinking the Thermoelectric Cooler Judson thermoelectric coolers dissipate up to 5 watts of power. Heat sinking is necessary to dissipate this power. Judson offers the following heat sinks to accomplish this task. HS1 Heat Sink for Judson 66S/66G Packages The HS1 heat sink is available for Judson Ge, InAs and HgCdTe TE cooled detectors mounted in the 66S and 66G packages. The heat sink is designed to provide easy heat sinking to the customer's bench top or optical system. Typical Setup with TC5 Automatic Temperature Control 19.99 POWER SUPPLIES S 115/230 V DETECTOR J1 GAIN SET THERM SET < <> > < <> > POWER DRIVER P/I CONTROLLER THERM SET SENSE < < > > THERM INT SET CURRENT SENSE CURRENT LIMIT SET CURRENT SET SENSE < <> > CURRENT LIMIT THERMISTOR SENSE THERMISTOR AMP Package pin configurations: See Product Outline Drawing supplied with detector. Caution: Observe cooler polarity and max. power rating. TC6 Miniature Temperature Controller SIGNAL GND. TC6 TEC TEMPERATURE CONTROLLER +5 VOLT SUPPLY VS = +5 VOLTS R3 PWR. GND. EXT. TEMP. SET RESISTOR P1 + SIGNAL GND. TEC MAXIMUM CURRENT ADJUSTMENT on 1.375 dia. P2 RT BRIDGE MONITOR RS TEMP. STABILIZED IND. TEC TEC CUR. MONITOR +5 VOLT REF. CUSTOMER SELECTED TEMPERATURE SET RESISTOR DETECTOR P3 TEMP. SET RES. MONITOR Threaded Bushing 7/8 - 28 UN Thread 1.8 dia. 1.0 dia. DETECTOR ASSEMBLY 1.59 to Detector Plane Detector Output FEA TURES FEATURES * Precise Temperature Control * Temperature Set with a Single Resistor * Operates with Most TEC Cooled Detectors * LED Temperature Stabilization * Maximum TEC Current Adjustable to 2 Amps * Detailed Instruction Manuat Provided HSA2 Heat Sink Assembly for Judson Thermoelectrically Cooled Detectors The HSA2 two-stage thermoelectric cooler and heat sink assembly is available for Judson TE cooled detectors. The assembly consists of the specified detector, a thermistor and a two-stage thermoelectric cooler mounted in a hermetic package with heat sink and detachable cables. The Model TC5 temperature controller is specifically designed for use with the 6 Bolt Holes HSA2. Equally Spaced * Temperature Stability to 0.02C * Single +5 Volt Power Supply Operation * Thermistor Bridge Monitor * TEC Current Monitor * Small Size CAUTION: Max. current for the TE2, TE3 and TE4 is 1.3 ampere. Max. current for the TE1 is 1.0 ampere. When using a one stage cooler, a series resistor needs to be installed with the TC to limit the max. current to 1.0 ampere. Cable length 15" nominal Front View (Cap Removed) 1.78 to Top of Threaded Bushing .25 ref. 2.03 ref. TE Cooler Power and Thermistor Cable length 45" nominal Protective Cap 1 2 3 4 5 Cooler Cooler + Thermistor Thermistor 6 7 8 Pin 2 Pin 4 Pin 7 Pin 8 9 Information in this document is believed to be reliable. However, no responsibility is assumed for possible inaccuracies or omission. Specifications are subject to change without notice. Judson Technologies, LLC 221 COMMERCE DRIVE MONTGOMERYVILLE, PA 18936-9641 TEL: 215-368-6901 * FAX: 215-362-6107 WWW.JUDTECH.COM 220-012104