Acoustically induced optical second harmonic generation in InAs crystals

Acoustically induced optical second harmonic generation (AIOSHG) in InAs single crystals was investigated. With increasing acoustical power, the AIOSHG for fundamental CO laser light (λ = 7.1 μm) increases and achieves its maximum value at acoustical power density about 1.70 W/cm2. The value of the AIOSHG for InAs was substantially higher than for key inorganic photo-refractive and ferroelectrics materials. With decreasing temperature, the AIOSHG signal strongly increases below 42 K. The AIOSHG maxima were observed at acoustical frequencies ranged at 7-11 kHz. Comparing the obtained results with the acoustically induced IR spectra at low temperature, one can conclude that the observed effect is associated with acoustically-induced phase transformations. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)