Papers by Keyword: GaAs Crystal

Abstract: We explore the terahertz (THz) wave generation based on surface-emitted difference frequency generation (SEDFG) in periodically-inverted GaAs crystals. One scheme applying collinear quasi phase matching (QPM) is proposed. The wave propagation of the higher frequency pump wave is parallel to the wave propagation of the lower frequency pump wave, and both of them are perpendicular to the domain wall of the nonlinear crystal. The THz wave is emitted perpendicular to the surface of the nonlinear crystal. We calculated the grating period of periodically-inverted GaAs at the range of 100-1000μm (0.3-3THz). Our estimates illustrate that THz wave output corresponds to the power conversion efficiency of 0.015% at a frequency of 1THz. The result is shown that this scheme is efficient to obtain THz wave.

Abstract: Compound semiconductor GaAs crystal was grown by the pulling-down method and the Φ2" GaAs boules were obtained. The growth defects, such as growth stripes, small facets, pits and dislocations, were observed. The pits on the surface of the boule was attributed to the water content of B2O3 encapsulant and the growth defects on the tail were associated with the evaporation of As due to GaAs decomposition. The average EPD (etch pit density) was measured less than 5000 cm-2, which shows the pulling-down method was a potential technique to grow high quality GaAs crystals.