OPTICAL MODULATOR

摘要

PURPOSE:To make intensity modulation of exit light by changing the refractive index of a semiconductor having a deep level by light and making use of Fabry- Perot interference. CONSTITUTION:This optical modulator modulates light by forming the deep level to capture electrons (or holes) in the semiconductor, exciting the electrons captured in the deep level by light to increase a free electron concn. and consequently to decrease the refractive index and making use of the Fabry-Perot interference. A GaAs film 5 doped with oxygen is grown to 10mum thickness by a liquid phase epitaxial method on a non-doped GaAs substrate 4 and part of the rear surface of the substrate is etched by 3mm diameter and is thereby thoroughly removed. A nonlinear effect appears between transmitted exit light 7 and semiconductor laser light 6 having 1.3mum wavelength if said incident light 6 is made incident on the substrate from the rear thereof. This device is thereby made applicable to not only the optical modulator but also a high- speed optical logical circuit element as well.