1.55-$\mu$ m GaNAsSb-Based Photoconductive Switch for Microwave Switching

We report a GaNAsSb-based photoconductive switch for microwave switching application. The GaNAsSb layer was grown by molecular beam epitaxy in conjunction with a radio-frequency plasma-assisted nitrogen source and a valved antimony cracker cell. The switch shows a maximum ON-OFF ratio of 9 dB at 1.5 GHz under 1.55-m laser excitation at 80 mW. The switch also shows a positive ON-OFF ratio up to 10 GHz. This is the first successful demonstration of a photoconductive switch for microwave switching application under 1.55- m wavelength excitation. Further analysis suggests that the high contact resistance may degrade the performance of the photoconductive switch.