| 摘要 |
PURPOSE:To enable injected carriers to be discharged from a junction at high speed and thereby to eliminate any optical switching delay to occur along with the recombination life of carriers, by allowing the base region of a junction type transistor to punch through, and thereby effecting a high-speed optical switching operation. CONSTITUTION:An emitter-collector junction which is formed by the layers 12 and 14 of a pnp transistor T composed of layers 12, 13 and 14 has a structure similar to one which forms a p-n junction of the light-emitting part of a laser. When light is emitted, an emitter terminal 8 is held at a high potential, while a base terminal 10 is held at a low potential. In this state, a p-n laser diode D emits light. At this time, a collector terminal 9 is held at a ground potential. To suspend the emission of light, the base 10 is raised to a high potential. In consequence, the base of the pnp transistor T punches through, so that the carriers trapped in the active layer 12 of InGaAsP are discharged to the ground through the collector terminal 9. |
