Reflection second-harmonic microscopy of individual semiconductor microstructures

Second-harmonic scanning optical microscopy in reflection is used to image at room temperature individual GaInP/GaAs microstructures formed on a GaAs (001) substrate. Second-harmonic images of individual microstructures are recorded along with first-harmonic images for four combinations of polarizations of the pump and second-harmonic radiation with different pump wavelengths in the range of 720-920 nm. We observe different second-harmonic images for different polarization configurations and their evolution when changing the pump wavelength. Comparing the dependencies of the second-harmonic signal from the bare sample surface with those related to the microstructures, we conclude that the second-harmonic radiation detected when illuminating the microstructures originates from the substrate at short wavelengths and directly from the microstructures at similar to 900 nm of the pump wavelength. The appearance of the second-harmonic images for different polarization configurations is used to discuss the nonlinear properties of the investigated microstructures. (C) 2001 American Institute of Physics.