Neutron and Gamma Radiation Effects on GaAlAs Laser Diodes.
Abstract
The effects of two kinds of radiation on the performance of double heterojunction aluminum-gallium-arsenide (AlGaAs) laser diodes were investigated. One set of diodes received neutron radiation in a nuclear reactor; another set was exposed to gamma radiation from a cobalt-60 source. Each set contained two types of lasers, an RCA C30127 and a Laser Diode Laboratories LCW-10, both designed to operate continuously at room temperature. At neutron fluences of 10 to the 14th power n/sq cm, both types of diodes showed significant decreases in power output and external quantum efficiency, and increases in threshold current. There was no significant change in bias voltage versus forward current or in spectral composition of the light outputs at neutron fluences up to 10 to the 15th power n/sq cm. Under gamma radiation, the C30127 laser exhibited rapid degradation. A dosage of 10 to the 4th power rad(Si) reduced the output power by half. Threshold current, efficiency, and intensity distribution were all adversely affected. The damage factor at constant voltage was 1.5 x 10 to the minus 7th power rad to the minus 1 power. The LCW-10 performance improved to a dosage of 10 to the 6th power rad(Si) before degradation began. After 10 to the 8th power rad(Si), power output was still comparable to preirradiation values. Beam characteristics were not appreciably altered. The damage factor at constant voltage was 4 x 10 to the minus 8th power rad to the minus 1 power.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1980
- Accession Number
- ADA091795
Entities
People
- Harro Ackerman
- Thomas E. Walsh Jr
Organizations
- Air Force Research Laboratory