SEMICONDUCTOR DIFFRACTION GRATING

摘要

PURPOSE:To make diffraction efficiency changeable by a reverse bias voltage by forming (+) conduction type semiconductor layers divided at a specified interval on a semiconductor layer of a (-) conduction type and providing an electrode layer and a voltage impressing device so that the p-n junction interface is reverse biased. CONSTITUTION:A p-InP: Zn (10<16>cm<-3> impurity concn.) crystal or the like is used as a substrate 1 and semiconductor layers 2 of n-InP: Sn (10<16>cm<-3> impurity concn.) or the like are formed thereon at every specified interval. Metallic electrode layers 3 consisting of 10% Sn/Au, etc. are formed on the layers 2 and an electrode layer 4 consisting of 10% Zn/Au is formed on the bottom surface of the substrate 1. When the p-n junction interface between the substrate 1 and the electrode layers is reverse biased by a voltage impressing device 5, a diffraction grating having the diffraction efficiency variable with the magnitude of the impressed voltage is obtd. The diffraction grating is thus made suitable as a diffraction grating particularly for a distribution feedback type semiconductor laser or the like which is a light source for stabilizing wavelength.