Complementary optical bistable switching and triode operation using LiNbO3directional coupler

Optical bistable switching and optical triode operation have been carried out using an optical directional coupler switch fabricated by Ti diffusion into LiNbO3at the 1.15 μm wavelength. The on/off ratio in conventional bistable switching was 10 dB and that in complementary bistable switching was 13 dB. Amplification gain in triode operation controlled by laser diode was 4.8 dB. Complementary operation was found to reduce feedback gain and to improve the on/off ratio in optical bistable switching.