1.06 Micron Photodetector Development.
Abstract
The design and progress towards realizing very high sensitivity 1.06 micrometers photodetectors are reported. This research program consists of two projects: a high sensitivity 5 MHz optical receiver and a field-assisted double heterojunction photocathode. A 5 MHz, 1.06 micrometers GaAsSb avalanche photodiode (APD) receiver was built, tested and its noise performance modeled to determine the ultimate performance achievable with this technology. The initial receiver was better than an equivalent Si APD receiver by a factor of 2, and this was with very low gain in the GaAsSb APD. Considerable overall improvement is predicted with higher gain APDs. Cs activation to achieve negative electron affinity (NEA) on heterojunction devices has been the major emphasis in the photocathode project. A sputter cleaning and annealing process was developed which produced excellent activations on GaAs. The first results are reported on a double heterojunction device which has been activated to NEA and operated in vacuum. This device exhibited very large dark current under applied bias which is not yet understood. Further work in understanding this dark current will be required in order to realize the potential of the field-assisted photocathode. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1976
- Accession Number
- ADA035772
Entities
People
- I. Deyhimy
- J. S. Harris Jr.
- K. Nakano
- L. O. Bubulac
- R. C. Eden