Self-mixing interference device with wave guide structure

摘要

The proposed self-mixing interference device comprises a substrate (1) with an integrated optical wave guide structure (3), a semiconductor laser source (2) arranged on a surface of the substrate (1) and emitting laser radiation towards said surface, and a photodetector arranged to detect intensity variations of the laser radiation. The wave guide structure (3) is optically connected to the laser source (2) and designed to guide the laser radiation emitted by the laser source to an out-coupling area at the surface of the substrate (1) and to guide a portion of the laser radiation scattered back from a target object (4) outside of the substrate (1) to re-enter the laser source (2). This self-mixing interference device can be realized with a lower total height compared to the known self-mixing interference devices.

主权项

1. A self-mixing interference device comprising:
a substrate with an integrated optical waveguide structure; a semiconductor laser source, arranged on a surface of said substrate and emitting laser radiation towards said surface; and a photodetector arranged to detect intensity variations of said laser radiation, wherein said waveguide structure is optically connected to said laser source and is configured to guide said laser radiation emitted by said laser source to an out-coupling area at said surface of said substrate for output of said laser radiation from said surface to a target object and to guide a portion of said laser radiation scattered back from the target object outside of said substrate to re-enter the laser source, wherein said waveguide structure includes a coupling structure located in the substrate to collimate said laser radiation and couple said collimated laser radiation at an output position of said surface out of said waveguide structure for output of said collimated laser radiation as parallel beams, wherein the coupling structure comprises at least one concave mirror and an optical deflecting element, the at least one concave mirror collimating the laser radiation and reflecting the collimated laser radiation toward said optical deflecting element for deflecting the laser radiation as it passes through the optical deflecting element for output of the collimated laser radiation from the optical deflecting element toward the target object as the parallel beams, and wherein the optical deflecting element includes a portion having a saw-tooth shape for receiving the collimated laser radiation from the at least one concave mirror and changing a direction of the collimated laser radiation for output of the collimated laser radiation from the optical deflecting element toward the target object as the parallel beams.