One-dimensional photonic crystal obtained by vertical anisotropic etching of silicon

Abstract

The potentialities of vertical anisotropic etching of (110) silicon for the fabrication of one-dimensional photonic crystal with a high refractive index contrast have been studied. It is shown that advances toward the near-IR spectral range are limited by the mechanical strength of thin silicon walls. The device structures obtained consist of 50 trenches, 114 µm deep, with 1.8-µm-thick Si walls (structure period 8 µm). Their reflectance spectra in the wavelength range 2.5–16.5 µm show good agreement with calculation results, although the main photonic band gap at λ≈28±10 µm remained outside the spectral region of measurements.