JPS6444904A - Device for coupling semiconductor laser and thin film waveguide - Google Patents

Abstract

PURPOSE:To flatly dispose respective elements on the same plane so that the convenience in packaging, the reduction of a thickness size, etc., are contrived by disposing a substrate of a semiconductor laser and a substrate of a thin film waveguide element in parallel with each other and providing a 90 deg. polarizer to the incident end face part of the thin film waveguide element. CONSTITUTION:The substrate 1 of the semiconductor laser and the substrate 2 of the thin film waveguide element are disposed in parallel with each other via a coupling lens 3 and the 90 deg. polarizer formed with a nonreflection preventive film 4 is stuck to the semiconductor laser side of the waveguide. Since semiconductor laser light is magnified in image and converted by the lens 3 and is projected to the waveguide, the mismatching of the mode field diameters of both the laser and the waveguide is decreased and the efficient image coupling is executed. The polarization direction of the semiconductor laser light is rotated 90 deg. by the 90 deg. polarizer and the coupling of the TM mode is executed on the thin film waveguide element. The Fresnel reflection at the end face of the waveguide is prevented by the nonreflection preventive film 4. The respective elements are thereby flatly disposed, by which the packaging is facilitated and the thickness is reduced.