One-dimensional photonic crystals based on porous n -type silicon

Abstract

Photonic crystals (PC) based on porous n-Si are fabricated and their structural, optical, and nonlinear optical properties are studied. The n-Si based PC composed of five pairs of layers with alternate porosity reveal a rather broad photonic band gap (PBG) of more than 100 nm and a reflectivity of up to 0.75. An average pore diameter of approximately 90 nm is found in n-Si based PC in contrast to mesoporous p-Si based PC, where pores are approximately 15 nm in diameter. Second-harmonic generation (SHG) spectroscopy reveals the enhancement of the SHG intensity by a factor of 102 at the blue edge of the PBG spectra which is attributed to the fulfillment of the phase matching conditions and the localization of the fundamental optical field in the PC. © 2005 American Institute of Physics.