Optical third-harmonic generation in reflection from (110) porous silicon layers

摘要

We studied third-harmonic generation (THG) in reflection geometry from porous silicon layers grown on (110) silicon substrates. A significant (more than 10 times) enhancement of the THG efficiency compared to crystalline silicon was found for the samples prepared on highly doped substrate, whereas for the samples grown on low-doped substrate the THG was much less effective than for crystalline silicon. This fact is connected with fluctuations of the electric field of the pump laser irradiation in the layers of anisotropically distributed silicon nanocrystals having different shape and sizes.