| 摘要 |
FIELD: optics.SUBSTANCE: photodetector contains an avalanche photodiode connected in series, an amplifier and a filter, a comparator, a pulse duration discriminator, a controlled power supply, a unit for signals' evaluation, a reference voltage source, a high-frequency generator and a synchronisation unit. Besides, the device also includes a series-connected additional amplifier and a detector. At that, the output of the detector is connected to the first input of the comparator, the input of the additional amplifier is connected to the filter. Used as filter is a band-pass filter with bandwidth around the middle of the operating frequency band of the amplifier frequencies.EFFECT: increase in signal/noise ratio upon adjustment of the multiplication factor of the avalanche photodiode directly by the received optical signal.1 cl, 2 dwg, 1 tbl |
