Abstract

A method is described for measuring flow velocity in a microscopic region by means of a differential-type laser velocimeter with a transmission grating. The principle of this velocimeter is described on the basis of spatial filtering of the transmission grating. The filtering characteristics are theoretically analyzed using a power spectral density function. The velocimeter is used to measure flow velocities and their spatial distributions in a small (700-μm diam) glass tube. The theoretical and experimental results show that this differential-type velocimeter is more suitable and practical than the conventional one for measuring the flow velocity in a small probe.

© 1985 Optical Society of America

Measurements of the velocity gradient in a microscopic region using a transmission grating

Yoshihisa Aizu, Tsuyoshi Ushizaka, and Toshimitsu Asakura
Appl. Opt. 24(5) 641-647 (1985)

Measurements of flow velocity in a microscopic region using a transmission grating: a practical velocimeter

Yoshihisa Aizu, Tsuyoshi Ushizaka, Toshimitsu Asakura, and Tomiyasu Koyama
Appl. Opt. 25(1) 31-38 (1986)

Measurements of flow velocity in a microscopic region using a transmission grating: elimination of directional ambiguity

Yoshihisa Aizu, Tsuyoshi Ushizaka, and Toshimitsu Asakura
Appl. Opt. 24(5) 636-640 (1985)

Measurements of flow velocity in a microscopic region using a transmission grating

Tsuyoshi Ushizaka and Toshimitsu Asakura
Appl. Opt. 22(12) 1870-1874 (1983)

Time-resolved crossed-beam thermal lens measurement as a nonintrusive probe of flow velocity

Wayne A. Weimer and Norman J. Dovichi
Appl. Opt. 24(18) 2981-2986 (1985)