An excited state Voigt optical filter at 1.5 μm

Abstract

An excited state Voigt atomic optical filter working at optical communication wavelength (1.5 μm) is realized. The filter achieves a peak transmittance of 53.5% with a double-peak structure, in which each one has a bandwidth of 600 MHz. Different from the Faraday anomalous dispersion optical filter, the magnetic field of the Voigt filter is perpendicular to the propagation direction of the light, which makes permanent magnets in the filter easier to realize and makes the filter better for engineering.