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Implementation of long-wavelength cut-off filters based on critical angle
Yanen Guo1, J A Dobrowolski, Li Li
1National Research Council of Canada, Ottawa, Ontario, Canada.
Applied Optics
|April 5, 2011
Summary
Researchers improved long-wavelength infrared cut-off filters by refining fabrication processes. Adjustments to design and deposition yielded more stable and higher-performing filters with extended transmission and rejection regions.
Area of Science:
- Optics and Photonics
- Materials Science
Background:
- Fabricating long-wavelength infrared cut-off filters using critical angle, refractive index dispersion, and thin-film interference presented challenges.
- Initial filter designs with layers between high-index prisms suffered from porous, rough thin films.
Purpose of the Study:
- To overcome limitations in previous filter fabrication attempts.
- To achieve improved and stable performance in long-wavelength infrared cut-off filters.
Main Methods:
- Modified the design of the filter structure.
- Adjusted thin-film deposition processes.
- Utilized optical contacting techniques.
Main Results:
- Successfully produced filters with reduced porosity and roughness.
- Minimized water vapor adsorption and associated absorption.
- Enabled easier and more reliable optical contacting.
Conclusions:
- Optimized design and deposition processes are crucial for high-performance infrared filters.
- The refined methods lead to filters with enhanced stability and functionality.
- This work advances the fabrication of specialized optical filters.
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