Si avalanche photodiode

Various eomplete photodiode modules are commereially available. They use Si PIN photodiodes at an internally generated reverse voltage in the range of 30 V, Si avalanche photodiodes at a voltage of 50 to 150 V, or fast InGaAs diodes. 

Figure 1. A - 87Rb levels used in the experiments (Di line Zeeman sublevels are not shown in this simplified scheme the ground-state hyperfine splitting is 6.835 GHz). The write (retrieve) laser and Stokes (anti-Stokes) beam are illustrated in red (blue). B - After the optical pumping pulse (provided by the retrieve laser), the 1.6/us-long write pulse is followed by the retrieve pulse after a controllable delay Td. C - Schematic of the experimental setup. SI, S2 (AS1, AS2) denote the avalanche photodiodes for the Stokes (anti-Stokes) light.

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