A photonic-crystal narrow-band optical filter

We propose and analyze a narrow-band optical filter based on a multilayer dielectric mirror deposited on a corrugated substrate with a period A. It is shown that, by optimizing the thickness of mirror layers and the corrugation depth, one can create a filter with a transmission band two orders of magnitude narrower than that of a standard plane filter with a half-wave layer sandwiched between dielectric multilayer mirrors with the same number of layers. We will also demonstrate that the range of angular tunability of the wavelength corresponding to maximum transmission is determined by the requirements to the magnitude of losses in this filter. In particular, with the magnitude of admissible losses equal to 1.5%, the wavelength tunability range may reach 4.7 nm for the transmission bandwidth of 0.08 nm.