CONFERENCE PROCEEDINGS
Advanced Search
Home > Journals > Opt. Eng. > Volume 57 > Issue 12 > Article
Open Access
6 December 2018 Performance characterization of tunable longwave infrared notch filters using quantum cascade lasers
Neelam Gupta, Mark S. Mirotznik
Author Affiliations +
Optical Engineering, Vol. 57, Issue 12, 127101 (December 2018). https://doi.org/10.1117/1.OE.57.12.127101
Abstract
We describe the design and performance characterization of spectrally tunable microengineered notch filters operating in the longwave infrared from 8 to 12 micron using quantum cascade lasers (QCLs) tunable over the full spectral range. The filter design is based on the guided mode resonance phenomenon. The device structure consists of a subwavelength dielectric grating on top of a planar waveguide using high-index transparent dielectric materials, i.e., germanium (Ge) and zinc selenide (ZnSe) with refractive indices of 4.0 and 2.4, respectively. The filters are designed to reflect the incident broadband light at one (or more) narrow spectral band while fully transmitting the rest of the light. Spectral tuning of the reflected wavelength is achieved by changing the angle of incidence by mechanically tilting the filter. Filters based on one-dimensional (1-D) gratings are polarization dependent and those based on two-dimensional (2-D) gratings are close to polarization independent. Simple two-layer antireflection coatings were applied to minimize reflections from the nonpatterned side of the filter substrate. Our experimental setup consisted of a commercial QCL system operating at room temperature, a microengineered filter, and an uncooled broadband sensor. We present the filter design and detailed characterization experiment, and compare the theoretical and experimental results for 1-D filters.
CC BY: © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
Citation Download Citation
Neelam Gupta and Mark S. Mirotznik "Performance characterization of tunable longwave infrared notch filters using quantum cascade lasers," Optical Engineering 57(12), 127101 (6 December 2018). https://doi.org/10.1117/1.OE.57.12.127101
Received: 21 September 2018; Accepted: 5 November 2018; Published: 6 December 2018
JOURNAL ARTICLE
 7 PAGES
DOWNLOAD PAPER SAVE TO MY LIBRARY
GET CITATION
Lens.org Logo
CITATIONS
Cited by 14 scholarly publications and 2 patents.
Advertisement
Advertisement
KEYWORDS
Optical filters
Quantum cascade lasers
Long wavelength infrared
Germanium
Linear filtering
Tunable filters
Infrared radiation
RELATED CONTENT
Subscribe to Digital Library
Receive Erratum Email Alert
Back to Top