Emission of terahertz-frequency electromagnetic radiation from bulk GaxIn1−xAs crystals
نویسندگان
چکیده
We report an experimental study of femtosecond optically excited emission of terahertz frequency electromagnetic radiation from GaxIn1−xAs bulk crystals with alloy composition in the range between 0 x 0.65. The terahertz-emission mechanisms in bulk GaxIn1−xAs were studied as a function of carrier mobility, carrier concentrations, band gap as well as polycrystal grain size. Our experiments and analysis demonstrate that optical rectification is the dominant terahertz-emission mechanism for GaxIn1−xAs with 0.01 x 0.43 while surface-field acceleration is dominant for GaxIn1−xAs with 0.43 x 0.64. The magnitude of terahertz emission due to optical rectification is a function of the polycrystal grain size of the GaxIn1−xAs samples. Terahertz emission from GaxIn1−xAs due to optical rectification is due to a 2 nonlinear optical process. Overall, terahertz emission from GaxIn1−xAs is maximized for x 0.1–0.3.
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