公开(公告)号：US11815399B2

公开(公告)日：2023-11-14

申请号：US17653645

申请日：2022-03-05

Applicant: Topcon Corporation

Inventor： Akira Takada

IPC: G01J3/45 ,  G01J3/02

CPC classification number: G01J3/45 ,  G01J3/021 ,  G01J3/0208

Abstract: A wavelength-swept light source is configured to generate light to be measured that is wavelength-swept coherent light with a wavelength periodically changed. The light to be measured is separated into a measurement section and a reference section that have different optical path lengths, and is then coupled in an interference section to generate interfering light. An analyzer performs a Fourier transform of interference signals of the interfering light, and acquires an actual measured noise floor value for each of the optical path length differences based on a point spread function. An estimated coherence time is determined so that an actual measured amplitude value of the noise floor value and a calculated amplitude value coincide with each other. Linewidth of the light emitted from the coherent light source is measured based on the estimated coherence time.

公开(公告)号：US12066739B2

公开(公告)日：2024-08-20

申请号：US17456380

申请日：2021-11-24

Applicant: Topcon Corporation

Inventor： Akira Takada

IPC: G02F1/29

CPC classification number: G02F1/292

Abstract: An optical scanner includes: a light source; a deflection element including a plurality of pixels arranged one-dimensionally or two-dimensionally; a one-cycle diffraction grating including, among the pixels, continuous N pixels, where N is a natural number of two or more; the one-cycle diffraction grating having a length d in the alignment direction that is smaller than a wavelength λ of the light emitted from the light source; and a phase modulation controller configured to control a phase modulation amount of each of the pixels. Incident light is emitted from the light source obliquely from the reflecting surface at an incident angle θ1. Sin θi+(λ/d)>1 or sin θi−(λ/d)>1 is satisfied.