Blue Phase Liquid Crystal Optical Switching Element
Solution Overview
Problem
Conventional optical beam switching technologies face issues with slow switching speed, non-uniform electric field distribution, phase distribution, crosstalk, and total internal reflection, especially when dealing with polymer-stabilized blue phase liquid crystals and oblique light angles, leading to performance degradation and inability to deflect optical beams effectively at large angles.
Innovation Solution
An optical beam switching element utilizing a columnar sloped member with a polarization switching element and a polarization grating, where polymer-stabilized blue phase liquid crystal is sandwiched between transparent electrodes, and a focusing polarization grating is used to correct walk-off and divergence, ensuring high-speed, wide-angle switching with minimal loss and reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If polymer-stabilized blue phase liquid crystal is used for high-speed switching, then switching speed is improved, but electrostriction occurs due to large electric field distribution near comb-teeth electrodes, degrading performance
Solution Approach 1:
The patent extracts and removes the comb-teeth electrode structure that causes non-uniform electric field distribution. Instead, it uses a uniform transparent electrode configuration that eliminates the harmful electrostriction effect while preserving the high-speed switching capability of polymer-stabilized blue phase liquid crystal.
Solution Approach 2:
The patent applies uniform electrode properties across the entire liquid crystal layer, ensuring consistent electric field distribution. This local quality uniformity prevents electrostriction and maintains reliable high-speed switching performance throughout the device.
2Adaptability or versatility
If large thickness of liquid crystal is used for long wavelengths, then wavelength coverage is improved, but electric field distribution becomes progressively larger, causing phase distribution and performance degradation
Solution Approach 1:
The patent ensures uniform electric field distribution across the entire liquid crystal layer, including regions with varying thickness for different wavelengths. This uniform field quality prevents phase distribution errors and maintains manufacturing precision even when accommodating long wavelengths.
3Power
If comb-teeth electrodes are used to generate in-plane electric field, then retardation is produced in blue phase liquid crystal, but large in-plane electric field distribution causes phase distribution and crosstalk
Solution Approach 1:
The patent removes the comb-teeth electrode configuration that generates harmful in-plane electric field distribution. It replaces this with a uniform transparent electrode setup that eliminates crosstalk and phase distribution while maintaining the necessary retardation effect through orthogonal electric field orientation.
Solution Approach 2:
Instead of generating the electric field in-plane as with comb-teeth electrodes, the patent inverts the approach by generating the electric field orthogonally to the plate electrodes. This inversion of field orientation eliminates the crosstalk problem while achieving the required optical modulation.
4Adaptability or versatility
If prism sheets are used with polymer-stabilized blue phase liquid crystal, then gradient properties are obtained, but optically refractive effects become non-uniform for oblique incoming light, causing phase distribution
Solution Approach 1:
The patent extracts and removes the prism sheet component that causes non-uniform optical refraction for oblique light. This elimination prevents phase distribution in the outgoing beam while preserving the gradient properties through alternative means in the electrode configuration.
5Device complexity
If optical switching engine assumes orthogonal incoming light, then structure is simplified, but deflection at large angles causes total internal reflection, preventing light extraction
Solution Approach 1:
The patent changes the operational parameters of the optical switching engine to accommodate large-angle deflection. By adjusting the electric field orientation and eliminating prism sheets, it enables reliable light extraction at large angles while maintaining structural simplicity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables high-speed, wide-angle optical beam switching with reduced walk-off and divergence, preventing total internal reflection and enhancing switching efficiency, allowing for reliable deflection of optical beams at large angles without significant loss or crosstalk.
Implementation Method 1
This liquid crystal takes advantage of the Kerr effect, and, when voltage is not applied to the electrodes 25 in FIG. 2, index ellipsoids 27 of blue phase liquid crystal 26 are spherical, and retardation does not occur at any light input angle (FIG. 2(A)).
Implementation Method 2
a polarization grating mounted to the second planar face, wherein the polarization grating comprises a director that produces birefringence
Data Source
AI summary
[Problem] Conventional multi-stage optical switching elements have had the problems that, when the number of polarized light beams becomes large, walkoff of light beams produced in middle stages is gradually amplified so that beams at the terminal end deviate from the opening surface and the configuration of the optical switching element itself becomes larger. [Solution] Developed is a 1×N light beam switching element, which has a cube-type modular structure comprising a corner cube and a cubical cube with roughly identical dimensions, which is one-dimensional, two-dimensional, and three-dimensional, and which is fast, highly efficient, wide-angled, and compact, by combining: a simple corner-cube reflection-type light beam switching element comprising a polymer-stabilized blue-phase liquid crystal layer sandwiched between two transparent electrodes in the form of parallel plates, a mirror, and a wedge-shaped prism; and a walkoff correction element in which a condensing-type polarization grating is arranged or affixed to a cubical.