Abstract

Photonic crystals remain one of the most actively discussed topics of the modern optics. In particular, they are very promising for the control of such nonlinear-optical processes as harmonic generation and light self-action as well as for sensor applications. Porous silicon (PS) produced by electrochemical etching of the crystalline silicon (c-Si) due to possibility of the pore filling with liquids and embedding nanoparticles is a very promising medium for the formation of the nanocomposites for various optical applications. Variation of the etching-current density results in variation of the PS layer porosity and its refractive index; alternating the high and low porosity samples we can form a photonic crystal. PS-based photonic crystal easily allows the phase matching to be reached, which was demonstrated in experiments on the second-harmonic (SH) enhancement [1]. The ordered pore propagation, which is typical for mesoporous silicon, causes strong birefringence of the PS layers; the photonic crystals consisting of the birefringent layers demonstrate photonic band gap (PBG) depending on the light polarization [2]. As a result, the harmonic generation in photonic crystals can be also controlled by the light polarization [3], which enriches phase-matching opportunities. New experimental geometries opened by photonic crystals with birefringent layers are very promising both for the enhancement of the nonlinear-optical signal in nanopomposite and for the development of novel sensors based on phase-matched interactions. Thus, features of the phase matching effect on the nonlinear-optical process efficiency in the photonic crystals formed by birefringent layers should be studied in more detail.

© 2009 IEEE