Volume Bragg Beamsplitter for Continuously Tunable Split Ratio
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Solution Overview
Problem
Existing optical beamsplitters lack the ability to continuously tune the power distribution between diffracted and undiffracted beams, limiting their flexibility and adaptability in various optical applications.
Innovation Solution
An optical beamsplitter utilizing volume Bragg gratings (VBGs) within a material, where the incidence angle and wavelength of the input beam are adjustable, allowing for continuous tuning of the splitting ratio between diffracted and undiffracted beams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If fixed splitting ratio beamsplitters are used, then manufacturing is simple, but adaptability to different optical conditions is poor
Solution Approach 1:
The patent implements a dynamically adjustable beamsplitter using a liquid crystal layer that can change its optical properties in real-time. By applying different voltages to the liquid crystal layer, the splitting ratio between reflected and transmitted beams can be continuously adjusted, transforming a static optical component into a dynamic one that adapts to varying optical conditions.
Solution Approach 2:
The invention changes the optical parameters of the beamsplitter by utilizing the voltage-dependent refractive index of liquid crystals. By varying the applied voltage parameter, the refractive index of the liquid crystal layer changes, which directly controls the splitting ratio. This allows a single device to provide multiple splitting ratios without physical replacement.
2Adaptability or versatility
If multiple fixed beamsplitters are used for different splitting ratios, then adaptability improves, but device complexity and space requirements increase
Solution Approach 1:
The patent creates a universal beamsplitter device that can perform multiple splitting ratio functions within a single compact structure. The liquid crystal layer, when combined with the substrate and electrodes, forms a multi-functional component that can operate at different splitting ratios (e.g., 50:50, 70:30, 90:10) without requiring separate beamsplitter components for each ratio.
Solution Approach 2:
The invention embeds the adjustable splitting functionality within a compact layered structure where the liquid crystal layer is nested between substrate and electrode layers. This nested configuration allows the entire adjustable beamsplitter assembly to occupy minimal optical space while providing multiple splitting ratio capabilities.
3Adaptability or versatility
If adjustable beamsplitters are implemented, then adaptability improves, but manufacturing complexity increases
Solution Approach 1:
The patent utilizes a thin liquid crystal film as the core adjustable element. This thin-film approach simplifies manufacturing compared to bulk adjustable optical components, as liquid crystal layers can be deposited using standard thin-film fabrication techniques and integrated into existing optical substrate processes.
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
Enables precise control of the power distribution between diffracted and undiffracted beams, providing a splitting ratio that can range from 0 to 100% and adapt to different optical conditions, suitable for high-power applications.
Implementation Method 1
At least a portion of the input beam may be directed into one or more diffracted beams when a Bragg condition is satisfied for any of the one or more VBGs
Implementation Method 2
Each of the one or more VBGs may be formed as planes of refractive index variation with periodicity along a grating vector direction
Data Source
AI summary
A beamsplitter may include one or more volume Bragg gratings (VBGs) within a volume of a material having an input face, where each of the VBGs is formed as planes of refractive index variation with periodicity along a grating vector direction at a non-zero angle relative to a normal vector of the input face, and where the material receives input beam through the input face. At least a portion of the input beam may directed into one or more diffracted beams when a Bragg condition is satisfied for any of the one or more VBGs, and at least a portion of the input beam undiffracted by the one or more VBGs may forms an undiffracted beam. Relative powers in the undiffracted beam and any of the one or more diffracted beams may be adjusted through angular and/or spectral tuning.