The feasibility of using InP: Fe photoconductive devices as high-speed microwave switches has been demonstrated in the 0.01 - 10 GHz frequency range, by fabricating a fiber optic compatible modified interdigitated gap (MIG) structure. Rise and fall times of less than 100 ps have been measured and a power switching ratio (PSWR) of 13 dB at 10 GHz has been achieved when illuminating the device with 10 mW of effective optical power (CW) from a semiconductor laser with a fiber pigtail.