The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Jun. 06, 2023

Filed:

Aug. 25, 2021
Applicant:

Seiko Epson Corporation, Tokyo, JP;

Inventor:

Kohei Yamada, Shiojiri, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01B 9/02001 (2022.01); H01S 5/00 (2006.01); G01P 3/36 (2006.01); G02F 2/00 (2006.01); G02F 1/11 (2006.01);
U.S. Cl.
CPC ...
G01B 9/0201 (2013.01); G01P 3/363 (2013.01); G02F 1/11 (2013.01); G02F 2/00 (2013.01); H01S 5/0085 (2013.01);
Abstract

A laser interferometer includes a light source that emits first laser light, an optical modulator that includes a vibrator and modulates the first laser light by using the vibrator to generate second laser light including a modulated signal, a photodetector that receives interference light between third laser light including a sample signal generated by reflecting the first laser light on an object and the second laser light to output a light reception signal, a demodulation circuit that demodulates the sample signal from the light reception signal based on a reference signal, and a signal generator that outputs the reference signal input to the demodulation circuit and outputs a drive signal input to the optical modulator, in which Vd/Vr<10, where Vr is a voltage of the reference signal and Vd is a voltage of the drive signal.


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