Ultranarrow bandpass filter with wide nontransmission region composed of randomly distributed layer thicknesses

Abstract

By introducing disorder into a periodic Fabry–Pérot type of ultranarrow bandpass (UNBP) filter, the nontransmission region of the filter can be remarkably enlarged while maintaining the UNBP. The filter that was used was fabricated by using electronic beam evaporation. The introduction of disorder into the periodic structure ensures that the nontransmission region is significantly extended by 14%, with a very narrow bandpass of full width at half maximum <1.9 nm and intensity=80%.