Semiconductor Optical Amplifier Space Switch With Symmetrical Thin-Film Resistive Current Injection

Experimental and simulated results of an amplified electro-optical spatial switch using pre-emphasis techniques are presented. A symmetrical thin-film resistor replaces the typical 47 Ω resistor used to match the impedance between the device (3 Ω) and the transmission lines (50 Ω), allowing fast injection of preimpulse and step currents in a semiconductor optical amplifier. This new construction reduces the parasitic elements from the mounting and enables the switch to achieve fast OFF-ON time (225 ps) and low overshoot (12%) with optimized pulse formats, reaching nearly Gaussian-response in electro-optical spatial switching.