SEMICONDUCTOR OPTICAL ELEMENT, INTEGRATED SEMICONDUCTOR OPTICAL ELEMENT, AND SEMICONDUCTOR OPTICAL ELEMENT MODULE

摘要

A semiconductor optical element includes an optical waveguide formed on a semiconductor substrate, which includes: a single mode guide portion which guides input light in a single mode; a curved portion disposed at a downstream side of the single mode guide portion in a waveguide direction of the light and guiding the light in a single mode; and a flared portion disposed at a downstream side of the curved portion in the waveguide direction and of which waveguide width is widened toward the waveguide direction, so that the flared portion can guide the light in a single mode at an light-input side and the flared portion can guide the light in a multi-mode at a light-output side. The input light is optically-amplified by each of the active layers in the single mode guide portion, the curved portion and the flared portion by an optically-amplifying effect of the active layers.