Engineering topics
Publications and source records attributed to Walsh, T. E..
Detection system, which incorporates advantages of microwave biasing, measures output of a carbon dioxide laser at 10.6 microns with a factor of 1,000 improvement in sensitivity. Material lifetime, rather than external circuitry, limits detector response time.
Mercury-doped germanium photodetector uses waveguide which increases the absorption of microwave energy within the photodetectors. Waveguide and photodetector are placed in liquid helium Dewar and cooled. A carbon dioxide laser is light source and klystron provides microwave energy. Measured response times are approximately 1 nanosecond.
Extrinsic photoconductive detectors, comparing performance for microwave and DC bias based on gain bandwidth product and SNR analysis
Gallium arsenide electro-optic modulator used for infrared lasers has a mica quarter-wave plate and two calcite polarizers to amplitude or phase modulate an infrared laser light source in the wavelength range from 1 to 3 microns. The large single crystal has uniformly high resistivities, is strain free, and comparable in quality to good optical glass.
Electro-optic coefficient of gallium arsenide measured at wavelengths from 2 to 12 microns by 10.6 micron laser modulator
Electro-optic modulators for IR region 0.9 to 16 microns constructed by using large single crystals of high resistivity gallium arsenide