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

Abstract

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