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Updated: Aug 7, 2026
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High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
Polarization-controlled switching between diffraction orders in transverse-periodically aligned nematic liquid
Hakob Sarkissian1, Svetlana V Serak, Nelson V Tabiryan
1Beam Engineering for Advanced Measurements Co., 809 South Orlando Avenue, Suite I, Winter Park, Florida 32789, USA. hakob@creol.ucf.edu
Optics Letters
|July 13, 2006
Summary
Transverse-periodic liquid crystals (LCs) act as high-efficiency diffraction gratings. Researchers demonstrated controlled switching of diffraction orders by altering incident light polarization, achieving a 267:1 contrast ratio.
Area of Science:
- Optics and Photonics
- Materials Science
- Liquid Crystal Displays
Background:
- Transverse-periodic-oriented nematic liquid crystals (LCs) function as efficient optical axis gratings.
- These gratings can achieve theoretical diffraction efficiencies of 100% in thin material layers.
Purpose of the Study:
- To experimentally demonstrate controllable switching between diffraction orders in LC gratings.
- To investigate the effect of incident beam polarization on diffraction patterns.
- To explore external control mechanisms for diffraction efficiency and direction.
Main Methods:
- Utilized a 1.5 micrometer thick LC grating with a 4 micrometer period.
- Employed an electrically controlled LC phase retarder to manipulate incident beam polarization.
- Experimentally switched diffraction orders by changing incident light from right-circular to left-circular polarization and vice versa.
Main Results:
- Achieved switching between +1st and -1st diffraction orders.
- Demonstrated external control without applying an electric field to the grating itself.
- Obtained a high contrast ratio of 267:1 for switching between orders.
- Measured a switching time of 6.6 ms using a He-Ne laser.
Conclusions:
- External control of diffraction orders in LC gratings is feasible via polarization manipulation.
- This method offers enhanced control without compromising grating quality.
- The demonstrated technique has potential applications in optical switching and beam steering.
