SOLID STATE TECHNIQUES FOR MODULATION AND DEMODULATION OF OPTICAL WAVES.
Abstract
Techniques for developing wideband optical modulators of KDP (potassium dihydrogen phosphate) were studied theoretically and experimentally. Forty-five degree, z-cut KDP modulators were built that required as little as 200 volts to achieve 100 percent optical modulation. Traveling-wave KDP and ADP (ammonium dihydrogen phosphate) modulators were tested up to 2 and 3 GHz. Crystalline quartz exhibited several properties valuable for achieving extremely wideband modulation. Homogeneous and inhomogeneous strains in cubic materials (e.g., HMTA and CuCl (hexamethylene-tetramine and copper chloride)) seriously degrade their performance as electro-optic modulators. In certain Perovskites, effects of such strains are only second-order near the ferroelectric transition temperature and under large bias fields. Ultrasonic time-variable phase diffraction gratings were produced in crystalline quartz. Techniques for fabricating fast semiconductor germanium and silicon diodes were developed. Silicon p-i-n diodes were studied. Explicit expressions for device efficiency, signal-to-noise ratio, and noise equivalent power (NEP) were derived as functions of bandwidth, load impedance, and other parameters. Low-noise, high-gain transistor amplifiers were designed to extract the optimum signal from the diodes. The avalanche mechanism was isolated and developed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1966
- Accession Number
- AD0489390
Entities
People
- Dayton D. Eden
Organizations
- Texas Instruments