Unpolarized resonant notch filters for the 8–12 µm spectral region
Abstract
The long-wave infrared (LWIR) spectral region spanning ∼ 8 − 12 µ m is useful for many scientific and industrial applications. As traditional multilayer film components are not straightforwardly realized at these bands, we provide design, fabrication, and testing of polarization independent bandstop filters based on the guided-mode resonance (GMR) effect. Focusing on the zero-contrast grating architecture, we successfully fabricate prototype filters in the Ge-on-ZnSe materials system. Applying mask-based photolithography and dry etching, photoresist patterns form the desired Ge grating structures. The resulting devices exhibit clean transmittance nulls and acceptably high sidebands. Moreover, we verify polarization independent notch filtering by assembling two identical GMR filters with gratings oriented orthogonally. This approach to realize effective GMR elements will be useful for various fields including photonic and optoelectronic devices operating in the LWIR region.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 06, 2020
- Source ID
- 10.1364/ol.398744
Entities
People
- K. J. Lee
- Natasha Gupta
- Robert Magnusson
- Y. H. Ko
Organizations
- United States Army Research Laboratory