Large optical anisotropy in the structure of 1D photonic crystal fabricated by vertical etching of silicon

Periodic structures of deep narrow grooves with vertical walls were prepared by liquid anisotropic etching of silicon. It has been shown experimentally that the obtained media possess properties of negative uniaxial crystal whose optical axis lies in the wafer plane. The media has huge optical anisotropy in the middle IR spectral range. Difference in effective refractive indicies of the ordinary and the extraordinary rays Δn is as about 1,5.