PM-200 Power Module Operating Instructions Terahertz Technologies Inc. 169 Clear Road, Oriskany, NY 13424 (315) 736-3642 FAX (315) 736-4078 E-mail tti@borg.com
Contents Introduction... 1 Specifications... 2 Unpackaging and Inspection...4 Principles of Operation... 5 Operating Considerations... 8 Service/Warranty Information...10
Introduction The PM-200 is a low cost power supply and control module that is used to power and control the gain of the P-444 Pyroelectric Energy Probe. The amplified detector signal is presented at a BNC output connector. This signal is calibrated in terms of Volts/Joule and may be measured with the aid of an oscilloscope or other instrumentation. The use of the PM-200 is appropriate in those cases where the accuracy and precision of the R-752 Energy readout is not required and low cost is the primary consideration. The P-444/PM-200 combination has six available ranges of sensitivity, 250 000 V/J, 25 000 V/J, 2 500 V/J, 250 V/J, 25 V/J, and 2.5 V/J. Page 1
PM-200 Specifications For use with:... P-444 Pyroelectric Probe Power Required... 12 VDC @ 50 ma, (supplied by the wallmount power supply provided) Output connector... Female BNC Output Impedance...100 Ohms Maximum Output Voltage...+5 V Dimensions... 6.1" x 3.7" x 1.6", 155 mm x 94mm x 41mm Weight... 8 oz., 227 g Operating Temperature... 0-40 C Limited Warranty... 2 Years Page 2
P-444 Specifications Active area... 0.5" diam., 1.27 cm Optical Pulse width... 0-2 ms Rep Rate... 0-75 pps Maximum Energy... 1 Joule Noise Equivalent Energy... 50 nj pk-pk Damage Threshold...1 MW/cm2 (100 ns pulse) Maximum Average Power...2 W Detector Uniformity... +/- 3% for 2 mm beam Spectral Response...350 to 2000nm, flat,+/- 3%, 200 nm to 20 microns, flat, +3,-12% Calibration Uncertainty...+/- 3% (250 000 V/J range, 633 nm) Operating Temperature... 0-40 C Size...4.5"x3"x2", 114mm x 76mm x 51mm Weight...1.5lbs.,.68Kg Page 3
Unpacking and Inspection Prior to shipment this instrument was inspected and found to be free of mechanical and electrical defects. Upon acceptance by the carrier he assumes responsibility for its safe arrival. After unpacking, examine the unit for any evidence of shipping damage. Should you receive this instrument in a damaged condition, apparent or concealed, it must be noted on the freight bill or express receipt and signed by the carrier's agent. Failure to do so could result in the carrier refusing to honor the claim. Upon filing a claim TTI should be notified. Page 4
Principles of Operation A pyroelectric detector consists of a thin slice of ferroelectric material that possesses a temperature dependent electrical polarization. When radiant energy is absorbed by the detector, (which is frequently painted black), a current is generated that is proportional to the time rate-of-change of the temperature of the material. If the black coating is a good absorber throughout the spectrum of interest the detector response will be constant as a function of wavelength. This property, in addition to its sensitivity and speed of response, is what makes the pyroelectric a superb detector for radiometric measurements. For purposes of making energy measurements, the output current is integrated thermally by the detector and by subsequent electronics to produce an output signal similar to that illustrated overleaf. The amplitude of the integrated detector output signal is proportional to the energy striking the detector surface. It is this signal that is measured and which is subsequently converted to units of Joules. Page 5
Input Optical Pulse Output from PM-200 showing cursors measuring a pulse height of 1.133 V. Figure 1 The baseline of the signal is not necessarily fixed since the detector responds to rate of change of temperature and not temperature itself. This is equivalent to an AC coupled signal. Therefore the step height must be measured with respect to the baseline just prior to the optical pulse. Page 6
Same signals as in Fig. 1 but at a slower sweep speed. Energy is 1.117 V / 250 000 V/J = 4.468 microjoules Figure 2 Page 7
Operating Considerations All detectors including this one are susceptible to damage from excess input power. While the study of laser damage thresholds is complex, there are several limits that, if observed, will prevent unnecessary and costly detector damage Damage to the detector surface from excess peak power density is the primary damage mechanism. Peak power density should not exceed 1 million watts per cm 2 at a pulse width of 100 ns. For an approximate guide to damage thresholds at other pulse widths consult figure 3. For a typical Gaussian beam, the peak power density may be approximated by : P = 8 E/πD 2 T where E is the pulse energy (Joules), D is the diameter of the beam between the half power points (centimeters), and T is the pulse duration (seconds). A test slide coated with the detector black is included with each P-444 to assist in determining the damage threshold of a given experimental arrangement. This slide should be inserted at the intended probe position and subjected to a number of pulses. If any sparking or change of appearance takes place, the beam must be attenuated before exposing the detector to the radiation. Page 8
Max Input Peak Power Density Pyroelectric Detector P-444 10000000 Watts/ Square Centimeter 1000000 100000 10000 1E-09 1E-08 1E-07 1E-06 1E-05 0.0001 0.001 Input Optical Pulse Width Figure 3 Page 9
Warranty And Repair Information REPAIR INFORMATION Products manufactured by Terahertz Technologies Inc. are designed and fabricated to provide reliable performance. However, in the event that service is required, both telephone technical assistance and factory repair services are available. Call (315) 736-3642 for information. For IN-WARRANTY REPAIRS, call us to obtain a Returned Material Authorization number, (SMA Number). All products are to be returned to TTI with freight charges pre-paid. Those products sent under warranty will be returned to our customers pre-paid. We cannot be responsible for returned products that do not reference the TTI SMA number. For OUT-OF-WARRANTY repairs, services are billable for both time and materials. Page 10
LIMITED WARRANTY TERAHERTZ TECHNOLOGIES INC. ( TTI ) WARRANTS THAT TO THE FIRST PURCHASER, FOR A PERIOD OF TWO YEARS FROM THE DATE OF RECEIPT, THAT THIS PRODUCT ( THE PRODUCT ) WILL BE FREE FROM DEFECTS IN MATERIALS AND MANUFACTURING. THE FOREGOING WARRANTY IS THE ONLY WARRANTY, EXPRESS OR IMPLIED, GIVEN BY TTI, I.E., THERE IS NO WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE. TTI HEREBY DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY OTHER THAN THE WARRANTY IN THE FIRST SENTENCE TO THE FULLEST EXTENT PERMITTED BY LAW. THE SOLE AND EXCLUSIVE REMEDY UNDER THIS WARRANTY IS REPAIR OR REPLACEMENT AT TTI S OPTION OF ANY PRODUCT THAT PROVES TO BE DEFECTIVE IN MATERIALS OR MANUFACTURING WITHIN TWO YEARS OF RECEIPT OF THE PRODUCT. NOTE: THIS WARRANTY DOES NOT APPLY TO ANY PRODUCT WHICH HAS BEEN SUBJECT TO MISHANDLING, MISUSE, OR SERVICE BY UNAUTHORIZED PERSONNEL OR TO ANY PRODUCT WHICH HAS BEEN DAMAGED, MODIFIED, ALTERED OR TAMPERED WITH. TO THE FULLEST EXTENT OF THE LAW, TTI DISCLAIMS ALL LIABILITY FOR ANY OTHER DIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES ALLEGED TO BE CAUSED BY A DEFECTIVE PRODUCT, I.E., TTI WILL NOT BE RESPONSIBLE FOR ANY PERSONAL INJURY, PROPERTY DAMAGE OTHER THAN THE COST OF REPLACING THE PRODUCT OR ANY OTHER MONETARY DAMAGE SUCH AS LOST WAGES OR PROFITS CAUSED BY ANY USE, ATTEMPTED USE OR INABILITY TO USE THE PRODUCT. NOTE: BY USING THE PRODUCT, YOU AGREE THAT REPAIR OR REPLACEMENT AT TTI S OPTION WILL FULLY SATISFY TTI S WARRANTY OBLIGATION TO YOU, WHETHER IN CONTRACT, TORT, NEGLIGENCE, STRICT LIABILITY OR OTHER APPLICABLE LAW Page 11