Effect of periodic array on the on-state resistances of GaAs photoconductive semiconductor switch based on total reflection theory

GaAs-based 5-mm-gap photoconductive semiconductor switches (PCSSs), with a thickness of 1 mm, are fabricated. A 60° beveling angle is used to make a periodic array of grooves on the surface of GaAs by mechanical processing. The laser beam should be reflected back when a vertical laser is illuminated on these grooves according to total internal reflection (TIR), which leads to an improvement of the light use efficiency (LUE) for the PCSS. The on-state resistance, ranging from 5.17 Ω to 2.14 Ω for the PCSSs, decreases in proportion with an increase of the duty cycle from 0% to 87.8%, where the pulse laser energy is 6.1 mJ at 1064 nm.