current preamplifier is necessary to realize a power measurement of the
incoming radiation. The amplifier consists of an IC as transimpedance
amplifier at the input side and two further voltage amplifier stages.
There are some additional components for a noise reduction and offset
regulation. In praxis the maximum amplification is limited by the cut
off-frequency. Highest amplification can only be realized for small
frequency intervals. For THz detectors in combination with a chopper
often the upper frequency is limited to values less than 50 Hz. For
such amplifiers conversion factors between 10 7 V/W and 1010 V/W can be realized.
sensitivity of the combination detector and preamplifier is determined
by multiplication of the current sensitivity of the detector and the
amplification of the current amplifier ( e.g. detector 10-6 A/W and CPA 109 V/A leads to a total sensitivity : 10-6A/W*109 V/A=1000 V/W). The amplification can be set by a switch.
The CPA needs an operating voltage ±15 V from an included separate power supply.
Power supply: ±15 V
Input connector: SMA or BNC
Output connector: BNC
Power connector: Lemo
The amplification can be set by a 4-step switch: e.g. 107... 1010
V/A ; the bandwidth is fixed* to e.g. 20Hz or 200 Hz. The detection
limit depends on the amplification, the bandwidth and detector diameter.
*please ask if you need other parameters