16
Appendix 1:
Optical Input
The optical input power striking the photodetector
is equal to the measured voltage divided by the
product of the gain knob setting times the multi-
plier [1 or 3] times the wavelength response factor.
For example, with these settings:
Gain knob: 10
4
Gain multiplier:
×
3
Response factor: 0.25 Volts/mW
DC output voltage : 2 V.
The optical input power therefore is equal to
2 V/(10
4
×
3
×
0.25)=270 nW.
Appendix 2:
Electrical Output
The photoreceiver has three knobs: a low-frequen-
cy corner, a high-frequency corner and a gain
knob, as well as a gain-multiplier switch.
Frequency Knobs
The upper left knob adjusts the low-frequency cor-
ner and the upper right knob adjusts the high-fre-
quency corner. The corner frequency is the fre-
quency where the response is down by 3 dB from
its mid-band value. Fig. 8 depicts the frequency
response with a roll-off at 6 dB/octave below the
low corner and above the high corner. To obtain
