Massachusetts Institute of Technology

USA As Represented by Secretary of the Navy

Sanders Associates Limited

Arthur Linz

Hans P Jenssen

Leon Esterowitz

Filbert J Bartoli

Roger E Allen

Charles S Naiman

Melvin R Kruer

Lee T Todd, Jr

Van O Nicolai

Lawrence S Goldberg

Donald E Castleberry

E P Chicklis

Eugene F Farrell

Improvements in Praseodymium solid state YLF lasers operating in the blueeen spectral region at room temperature and providing short pulses useful for underwater communication and detection systems. A dye laser with a narrow spectral output matched to the absorption spectra of the solid state laser is provided as a laser pump. The Pr doped YLF crystal of the solid state laser is physically oriented so it can be longitudinally pumped by light polarized parallel to the c-axis of the crystal, and the solid state laser is equipped with special spectrally selective mirrors. The foregoing and other modifications of prior Pr solid state laser systems provide increased efficiency and power output.

Praseodymium blue-green laser system

A room temperature opticaly pumped solid state laser operating in the 0.8 to 0.9 micron region with inherently low beam divergence enchances covert laser systems because of compatability with high quantum efficiency low noise photocathodes.

Laser

An optically pumped crystalline laser that includes a small single crystal section of a polygonal cylinder; the dimensions of the crystal section and the index of refraction of the crystal and the medium surrounding the crystal are such that there is formed a dielectric resonator that is totally reflective for a small number of modes. The material of which the crystal section is composed is one that is capable of being made optically thick in thin sections. The resonator is optically pumped and the lasing radiation therein is coupled to an optical element that is placed in close proximity thereto by virtue of an evanescent field that arises from the lasing action in the resonator.

Miniature crystalline laser

A process for preparing cathodochromic materials whereby coloration properties of the materials are enhanced by a low-temperature re-crystallization process. Crystalline powders formed using either hydrothermal or sintering growth techniques are hydrothermally re-crystallized at a temperature sufficiently high and for a time sufficiently long to effect re-crystallization. The temperature range for hydrothermal re-crystallization is 60.degree.C to 300.degree.C and the re-crystallization growth time is at least the order of 12 hours and, more typically, the order of three days. There is shown a cathode ray tube employing said materials.

Process for preparing cathodochromic sodalite

Growing community of inventors

Winchester, MA, United States of America

Arthur Linz