Transmission Second Harmonic Generation in Cd_1-xMn_xTe at 1.064 µm

Abstract

Second harmonic generation, created by nanosecond Nd : YAG laser pulses at 1.064 pm with relatively low intensity in Cd1-xMnxTe bulk crystals and thin layers was measured in transmission geometry. The effect practically occurs in a very thin surface layer of the material and it is used as a relatively straightforward method of layer quality characterization. It is shown that the angular dependence of the second harmonic generation intensity in thin layers of CdTe with good crystallographic (and optical) quality agrees very well with the theory in contrary to the samples with some distortions from the ideal structure which exhibits large distortions from the theory.PACS numbers: 42.65. Ky, 68.70.+w Recently, nonlinear properties of thin layers and quantum structures of various II-VI and III-V semiconductors attracted considerable attention due to possible application in a variety of fields. Relatively high electro-optic coefficient of these materials and relatively fast optical response make them attractive for devices used in optical communication, data processing, real time optical processing and optical limiting. Recent studies [1][2][3] show that cadmium manganeSe telluride exhibits strong nonlinear response in the visible and in the near-infrared. These materials may be of interest since it is possible to control its forbidden gap by the manganese content thus enhancing a nonlinear response due to band-to-band optical transitions.It has been recently shown that the second order nonlinear susceptibility coefficients for CdMnTe crystals are higher than these for CdTe [4] which makes this material even more attractive for applicationS.CdMnTe crystals were found to generate efficiently second harmonic in the infrared, excited by CO2 laser radiation at 10.6 µm. In this paper we show that CdMnTe crystals, grown by the Bridgman technique and molecular beam epitaxy (423)