Vladimir S. Dneprovskii . Nonlinear optical properties of semiconductors and semiconductor nanostructures. Strong optical nonlinearities in semiconductor quantum wires and dots. Gain and laser emission of semiconductor quantum wires and dots. ... Discrete optical transitions between the energy levels of size quantization in quantum dots and wires have been observed in the samples with great dispersion of the size of nanostructures using picosecond laser saturation spectroscopy method. ...