9. Laser Diode Laser Diodes include Photodiodes for feedback to insure consistent output.
10.
11.
12. Avalanche photodiode-2 Stabilisation of working point of APD: . Gain =75 Temperature stabilisation. Thermoelectrically cooler stabilisation system is inside of APD module AVALANCHE PHOTO DIODE
13. System Comparison (OC3 1km products) OpticalAccess ICS LightPointer Transmit Power (mW) 10 (10 dBm) 100 (20 dBm) 4 (6 dBm) Beam Diverg (mrad) 2.5 11 3 Receive Area (cm^2) 52 232 200 Min Recv Power (nW) 100 (-40 dBm) 32 (-45 dBm) 50 (-43 dBm) Price $19.5k $25k $24k
14.
15. Laser Link Geometry Critical Design Parameters Beam Divergence = 3 mrad Diameter = 3 m Beam area = 70686 cm 2 Distance = 1km Receive area = 200 cm 2 Transmit Power Receiver sensitivity
16.
17.
18.
19.
20. Uplink/Downlink Data Processing Sequence Bits Bit Encoder to Symbol LASER Transfer Optics Channel (Atmos.) Receiving Optics Amplifier Symbol Recovery Error Correction Bits