Rod lens type photo wave meter

Abstract

Abstract PURPOSE: To obtain a small wave meter with a sufficient resolving power and without an effect of mode difference by setting a rod lens, the end face of which is provided with a grid, and an image element that receives diffracted rays produced by the said grid. CONSTITUTION: The grid 3 is formed on the end face 2 of the rod lens 1. An optical fiber 5 is connected to the opposite face 4, incident rays are refracted in the lens and become parallel rays inside of the end face 2. The length of rod lens is made slightly longer than 0.25 pitches so that rays are converged at the end face 2. The rays are diffracted by the grid 3 and are received by the image element 7 at the focusing position. When the optical fiber is located at a distance from the center of the end face 4, the rays can be obliquely applied to the grid 3 and can be diffracted in the direction perpendicular to the grid, the relation between the wave length and the displacement on the image element becomes linear. The interference length between the rays and the grid is several millimeters, a sufficient resolving power can be obtained. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Ritsuo Hasumi

Bibliographic Details