High-resolution displacement measurement using mode interference in the optical waveguide

Author

Doi, Masaaki ; Iwasaki, Yutaka ; Shionoya, Takashi ; Okamoto, Kazuya

Author_Institution

Optomech. R&D Dept., Nikon Corp., Tokyo, Japan

Volume

9

Issue

5

fYear

1997

fDate

5/1/1997 12:00:00 AM

Firstpage

651

Lastpage

653

Abstract

Using an optical waveguide, high-resolution displacement measurement is achieved for the first time. The measurement principle is based on the interference between the two (even and odd) modes in the double-mode waveguide. After the light from a laser diode is focused onto the object to be measured, the wavefront gradient of the reflected light is detected using a Ti-indiffused LiNbO/sub 3/ channel waveguide. Although this optical measurement system is very simple, very high resolution (of less than 1 mn) is obtained. Besides, the characteristics of the measurement system do not depend on the surface condition of the object.

Keywords

diffusion; displacement measurement; lithium compounds; measurement theory; optical resolving power; optical sensors; optical waveguides; titanium; LiNbO/sub 3/:Ti; Ti-indiffused LiNbO/sub 3/ channel waveguide; double-mode waveguide; even modes; high-resolution displacement measurement; laser diode focusing; measurement principle; measurement system; mode interference; odd modes; optical displacement sensors; optical measurement system; optical waveguide; reflected light; surface condition; very high resolution; wavefront gradient; Diode lasers; Displacement measurement; Integrated optics; Interference; Laser excitation; Optical modulation; Optical sensors; Optical surface waves; Optical waveguides; Phase modulation;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/68.588181

Filename

588181