Optical Switching and Spatial Routing by a Delay-Controlled Optical Emitter

Semiconductor Laser or Light Emitting Diodes, (LEDs) as active elements of optical switches or spatial routing devices are widely used in integrated optical circuitry. Electro-optic, magneto-optic, mechanical or other methods are applied for that purpose. The present paper deals with a novel effect, which appears in the light field of a. c. driven luminescence emitters in Fabry-Perot structure under electrical excitation depending on time (a.c.), characterized because the light band emitted on the side face of the device moves up and down due to the finite diffusion velocity of the injected excess minority carriers. The combination of such emitter with a portioned detector element, allows spatial routing between these two detector segments. Particular emphasis is laid on a theoretical treatment of light propagation inside the emitter bulk which finally allows the construction of the light field intensity on the side face of the Fabry-Perot body, necessary to prove the proposed effect.