Figure 2: Schematic representation of the fast-gated experimental set-up.
From: Practical photon number detection with electric field-modulated silicon avalanche photodiodes
A bias signal, Vapd, composed of a dc component and a 500-MHz alternating signal is applied to the electric field-modulated Si-APD to periodically bias it above the breakdown voltage, Vbr, and a synchronized laser emits 15-ps pulses at 600 nm. The detector response is sensed as a voltage across a resistor, R, and a self-differencing circuit is used to remove the large capacitive response to the alternating bias signal. The typical output as acquired by a fast oscilloscope is also shown.
