| 摘要 |
PURPOSE:To obtain the semiconductor optical integrated circuit for a coherent optical communication receiver which is easily manufactured and highly homogeneous and has high performance by forming a polarization beam splitter of a Y-branch optical waveguide consisting of an optical guide layer which has superlattice structure and a clad layer having a lower refractive index than the optical guide layer, and making the superlattice structure of the optical guide layer disappear at part of the Y branch part by crystal mixture. CONSTITUTION:This semiconductor optical integrated circuit is the semiconductor integrated circuit for the coherent optical communication receiver where the polarization beam splitter 1, a 3dB coupler 2, and the optical waveguide 3 are integrated on a semiconductor substrate 10 made of InP and the optical waveguide 3 consists of the light guide layer 12 composed of an InGaAs(P)/InP superlattice and 1st and 2nd clad layers 11 and 13 made of InP; and the 2nd upper clad layer is in fundamental structure of a rib type optical waveguide consisting of projection stripe structure, the polarization beam splitter 1 forms the Y branch structure, and the superlattice structure of said optical guide layer 12 disappears at part of the Y branch part by crystal mixture. Thus, the part of the Y branch part of the superlattice structure waveguide is formed of mixed crystal to totally reflect waveguide light in TE mode and transmit waveguide light in TM mode, so that the polarization beam splitter can be manufactured. |
