LIGHT SEMICONDUCTOR ELEMENT

摘要

PROBLEM TO BE SOLVED: To make stop sizes to be symmetrical without increasing the series resistance of a light semiconductor element on the light semiconductor element. SOLUTION: A taper waveguide part 6 where the size of a core layer 2 constituted of more than one layer for guiding light continuously reduces toward the outgoing end face of light is integrated on an n-type semiconductor substrate 1. A refractive index control layer 5 having higher refractive index than the n-type semiconductor substrate 1 is provided between the core layer 2 and the n-type semiconductor substrate 1 only in the taper waveguide part 6 and at least at the tip part of the taper waveguide part 6.