GTE GOVERNMENT SYSTEMS CORP MOUNTAIN VIEW CA SYLVANIA SYSTEMS GROUP-WESTERN D IV
The sun pumped NdYAG laser developed on the previous program, AF contract F33615-72-1240, produced a fundamental mode output of 0.8 watts. This performance represented a multimode to TEMsub 00 mode conversion efficiency of about 17 percent in contrast to the 40 to 45 percent conversion which conductively cooled, lamp pumped lasers had demonstrated. The principal objectives of the work described in this report were to increase the TEM sub 00 mode output of the sun pumped laser and to develop and deliver a demonstration model laser. Operating in a straight cavity configuration and pumped by a 24 inch diameter telescope, the demonstration laser produced a polarized TEM sub 00 mode output of 2.05 watts at 1.06 microns. This improved fundamental mode performance was obtained by reducing the thermal-optic distortion caused by non-uniform bonding of the laser rod to the heat sink and by increasing the solar collection and relay efficiency. Frequency doubled operation of the laser was also demonstrated with up to 0.43 watts second harmonic output power being obtained.