Fast polarization independent tunable liquid crystal Solc filter using Sagnac configuration

Area of Science:

• Optical Engineering
• Imaging Systems
• Materials Science

Background:

• Narrowband tunable filters are crucial for multispectral imaging (MSI) and hyperspectral imaging (HSI).
• Existing filters face challenges like low optical throughput, slow response times, and limited tunability.
• Liquid crystal (LC) wave plates are used in tunable filter designs.

Purpose of the Study:

• To develop a fast, polarization-independent narrowband tunable filter.
• To overcome the limitations of existing tunable filters for HSI and MSI.
• To enhance optical throughput and reduce response time.

Main Methods:

• Employed a common path Sagnac interferometer setup.
• Integrated liquid crystal (LC) wave plates in folded and fan Solc configurations.
• Utilized both S- and P-polarization components.

Main Results:

• Achieved a fast and polarization-independent narrowband tunable filter.
• Demonstrated full tunability across the visible spectrum with multiple transmission peaks.
• Obtained twice the optical throughput compared to polarization-dependent Solc filters.
• Enabled shorter response times due to enhanced throughput allowing thinner LC retarders.
• Sagnac configuration facilitated miniaturization and reduced sensitivity to LC thickness variations.

Conclusions:

• The Sagnac common path configuration offers a promising solution for advanced tunable filters.
• This approach significantly improves performance metrics critical for HSI and MSI applications.
• The developed filter addresses key limitations, paving the way for more capable imaging systems.