Modeling of optoelectronic switch with PIN photodiode and GaAs MESFET transmission gate

A broadband and high-isolation optoelectronic switch, which consists of a PW photodiode and a GaAs MESFET in common gate configuration as a transmission gate, was theoretically and experimentally investigated. An analytical model has been developed to calculate the isolation level of the switch. The influences on the isolation level from different device parameters were studied. Experimental results obtained using commercial components validate the operation of the proposed switch. Measured isolation of 70 dB at 300 kHz and 55 dB up to 1.0 GHz were achieved. Good agreement has been obtained between the measured and calculated results and therefore the model developed has been validated.