Pump Lamps for Nd:YAG Lasers.
Abstract
This program is the second in a series designed to develop CW long-life, high-efficiency, low threshold power, Nd:YAG laser pump lamps for communications use. The goal for the space communications project (to be reached by 1975) is 1 watt laser output in the TEM sub 00 mode for 250 watts input. The laser rod is currently 50 mm x 3 mm diameter. The lamp arc length required is currently 1.9 inches. The desired lamp life is 3,000 hours. The prior program optimized efficiency. The main objective of this program was to improve the lifetime of the alkali metal vapor laser pump lamp. Lamp life tests were run at an inside wall loading of 33W/sq cm, which corresponds to 200 and 250 watts input power respectively for 4 mm and for 5 mm bore lamps. At the beginning of the program lamp lifetimes of 100 hours in a freely radiating condition were obtained. After failure mechanisms were analyzed, two lamps with a modified design were constructed and were operated in quartz vacuum jackets for 1065 and 3860 hours, respectively. Reactions and 'checks' on the envelope interior indicated that further improvements in lamp processing and/or a reduction in wall loading are necessary. Such improvements, in conjunction with the use of a new sapphire polishing technique developed on this program and further improvements in lamp design, should result in long-lived lamps with much less optical deterioration.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1974
- Accession Number
- AD0922391
Entities
People
- Carl Kretschmer
- Lowell Noble