Accession Number : AD0917451

Title :   Space Laser Rod Composition Evaluation.

Descriptive Note : Final technical rept. Jan 72-Jul 73,

Corporate Author : AIR FORCE AVIONICS LAB WRIGHT-PATTERSON AFB OH

Personal Author(s) : Remski, Richard L. ; Smith, Donald J.

Report Date : JAN 1974

Pagination or Media Count : 59

Abstract : This technical report describes the results of a program to determine the optimum concentration of active ions in Nd:YAG for specific application to the space communication laser transmitter. Within the constraints imposed by system power budget and size considerations, laser rods 3mm in diameter and 50 mm long were tested on passive and active bases. Active laser testing was performed with potassium-rubidium (K-Rb) vapor lamps spectrally matched to the neodymium excitation spectrum. As a concomitant experiment, the K-Rb lamps were evaluated to indentify aging and degradation behavior so that these effects could be separated from the effects of concentration on performance. A total of five lamps were used in the experiments, and the life history and performance of these lamps is reported. In excess of 600 hours of operation with K-Rb lamps was accumulated. The primary conclusion from this study is that in this application, a slight increase in neodymium concentration enhances performance. Typical standard composition rods contain 0.9 to 1.0 atomic % Nd; performance increases approximately 10% with dopings on the order of 1.1 atomic %. The occurrence of this peak is a tradeoff between increasing coupling efficiency and decreasing fluorescent lifetime. Concentration effects, however, are of less significance than overall optical quality of the material; increasing doping with decreased optical quality wll offer a net loss in performance. (Author)

Descriptors :   *SPACE COMMUNICATIONS), (*NEODYMIUM LASERS, YTTRIUM ALUMINUM GARNET), (*LASER COMMUNICATIONS, INFRARED LASERS, LAMPS, SPACEBORNE, RODS, POTASSIUM, RUBIDIUM, DOPING, INTERFEROMETERS, PASSIVE SYSTEMS, IONS, ABSORPTION, POWER, CRYSTALS, TRANSMITTERS, LIFE TESTS, MODULATORS, DISTRIBUTION, EXCITATION, DEGRADATION, AGING(MATERIALS).

Subject Categories : Lasers and Masers
      Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE