Optical Microwave Interactions in Semiconductor Devices.
Abstract
The results of an extensive characterization of high-speed analog modulation of (GaAl)As injection lasers, high speed optical detectors, and mode-locking of (GaAl) as injection lasers are presented. Commercial (GaAl)As injection lasers have been successfully modulated up to 5 GHz. The 5 GHz value represents a practical upper limit to the modulation bandwidth of existing commercial lasers. We also characterized the laser equivalent circuit and found that the parasitics play a significant role in the high-speed modulation of the injection laser. High-speed optical detectors were characterized, and we found that some commerical p-n junction detectors can respond to analog modulated optical signals at frequencies beyond 7 GHz. We characterized the optical response of GaAs MESFETs and found that they can respond to analog modulated optical signals at frequencies beyond 4 GHz with a sensitivity comparable to the best p-n junction detectors. Photoconductivity is the mechanism responsible for the optical response. We compared our experimental results with predictions from a simple theory and found them to agree in many instances. We believe that a photoconductive detector with an optimized geometry can be used in microwave-optical analog signal processing systems. A theoretical and experimental study of mode locking in (GaAl)As injection lasers was performed. Our results indicate that the mode locking of (GaAl)As injection lasers is related to either saturable absorbing or electron trap defects within the active region of the laser. These defects are also responsible for self-pulsations in injection lasers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1980
- Accession Number
- ADA092690
Entities
People
- C. W. Slayman
- H. W. Yen
- L. Figueroa
Organizations
- HRL Laboratories