Freddie W. Smith

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An analysis has been carried out of optical heterodyne conversion with an interdigitated-electrode photomixer made from low-temperature-grown (LTG) GaAs and pumped by two continuous-wave, frequency-offset pump lasers. The analytic prediction is in excellent agreement with the experimental results obtained recently on a photomixer having 1.0~pm-wide(More)
A cw output power up to 0.8 mW is obtained from a low-temperature-grown (LTG) GaAs, 0.3 ,um gap, interdigitated-electrode photomixer operating at room temperature and pumped by two modes of a Ti:AlaOs laser separated in frequency by 0.2 GHz. The output power and associated optical-to-electrical conversion efficiency of 1% represent more than a sixfold(More)
We report on the generation of 825 V electrical pulses with 1.4 ps rise time and 4.0 ps duration using a pulse-biased low-temperature-grown GaAs photoconductive switch triggered by an amplified femtosecond dye laser. Dependence of the pulse shape on both electric field and optical energy is observed and discussed. In recent years many applications have(More)
This letter reports the time dependence of the surface Fermi level of GaAs grown by molecular-beam epitaxy and then exposed to atmosphere. The sheet resistance of sample structures for field effect transistors alternately increased, decreased, increased, and decreased to become nearly constant after about 500 h. These changes correspond to the surface Fermi(More)
To determine parameters that would assure sterility of a sealed seam of film for application in "split-seam entry," spores of Bacillus subtilis var. niger were sprayed onto pieces of Kapton and Teflon film. Short-time, high-temperature (200 to 270 C) exposures were made with film pieces between aluminum blocks in a hot-air oven, and the D and z values were(More)