Multifrequency lasers for holographic contouring

Abstract

Abstract A ruby or other solid laser is made to generate two or more closely adjacent optical frequencies. By illuminating an object to be recorded holographically with the laser light, range contours are generated when the hologram is reconstructed. The range contours can be made to have distances on the order of 5 millimeters or more by utilizing a ruby laser. To this end, one of the two boundaries of the optical cavity for the laser is formed by a suitable mode selector, such, for example, as a Fabry-Perot resonant reflector, a prism or a grating. The thickness of the resonant reflector is so selected that two or more frequencies may be generated within the lasing linewidth of the laser. Preferably, in order to obtain better contrast, the optical length of the cavity is a multiple of the optical thickness of the resonant reflector. The invention described herein was made in the performance of work under a NASA contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 U.S.C. 2457).

Inventors

• 👤 Lee O Heflinger
• 👤 Ralph F Wuerker

Bibliographic Details