Experimental optical transistor for all-optical SiC ETO thyristor

A high-current and low on-state voltage optical transistor is provided in this paper for high-power applications. The structure of this device includes a twostage transistor in which the first stage is triggered optically using an infrared laser of 808-nm wavelength. The photogenerated current in the first stage drives the second stage of the optical transistor for current amplification. The on-state voltage of the proposed two-stage optical transistor is found to be 1.12 V at 50 A. The results show that a single-pipe laser with a low optical power of 2 W is sufficient to trigger this high-current optical switch. This can give us more flexibility to achieve an optimal tradeoff between the on-state voltage and delay times. The experimental results show that the optical transistor has a breakdown voltage of 70 V and can operate at frequencies higher than 10 kHz. This makes it potentially suitable as an optical gate driver for applications including but not limited to pulsed power and seriesconnection of power semiconductor devices for voltage scaling, and as an auxiliary optical-triggering device for anodeor even gate-current modulation of a highfrequency and high-power all-optical emitter turn-off (ETO) thyristor.