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Updated: Jun 12, 2026
15:25
Design and Characterization Methodology for Efficient Wide Range Tunable MEMS Filters
Published on: February 4, 2018
Summary
This study compares shortwave pass filters, including basic designs and rugate filter approximations. Different discrete index approximations to rugate filters were found to vary in their shortwave passband bandwidth.
Area of Science:
- Optical Engineering
- Materials Science
Background:
- Shortwave pass filters are crucial optical components.
- Basic designs utilize alternating low (L) and high (H) index quarterwave layers.
- Passband width is limited by rejection bands, but can be extended with intermediate indices.
Purpose of the Study:
- To compare discrete index approximations of rugate filters.
- To analyze the impact of different approximations on passband characteristics.
Main Methods:
- Design and simulation of basic shortwave pass filters.
- Approximation of continuous index profiles (rugate filters) using discrete layers.
- Comparison of four discrete index approximations to the rugate filter.
Main Results:
- Basic filters have passbands limited by third-order rejection bands.
- Subdividing basic periods with intermediate indices can narrow the passband.
- Four discrete rugate filter approximations exhibit differences in shortwave passband bandwidth.
Conclusions:
- Discrete approximations of rugate filters offer alternative designs.
- The choice of discrete approximation impacts the resulting passband width.
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