Light switching via thermo-optic effect of micromachined silicon prism

This letter presents an optical switch using total internal reflection (TIR) via thermo-optic effect (TOE). The switching function is obtained by changing the refractive index of silicon prism via TOE to switch the light across the TIR state. The structure is fabricated by microelectromechanical systems technology. The switch measures a cross talk of > 30 dB and an extinction ratio of > 40 dB but exhibits high insertion losses of 31.67 and 18.95 dB in the TIR and transmission states, respectively. Compared with conventional micromechanical and light-tuned switches, this switch is unique in mechanism and free of mechanical instability.