Semiconductor Physics, Quantum Electronics & Optoelectronics. 2008. V. 11, N 1. P. 023-025.
Selective unequal-thickness thin-film filters
for IR spectral region
1Institute of Telecommunications and Radio, Engineering Department of Photonics
Lviv Polytechnic National University, 12, Bandera str., 79013 Lviv, Ukraine
Phone: 8-032-2582581, e-mail: yaremchuk@polynet.lviv.ua
Abstract. A new five-layer structure of the dielectric interference filter for the infra-red
region of spectrum is investigated. The main spectral parameters of such a narrow-band
filter are determined. The dependence of the transmission band half-width on the
thickness of a dividing layer in this system is investigated. It is shown that, in the case of
the application of PbTe, GeTe, and SnTe layers with a given thickness; their number can
be limited to five at providing the necessary selectivity of the filter: practically the 100-%
transmission at the resonance frequency and 0.005 % outside the transmission band.
Keywords: interference filter, narrow-band filter.
|