Optical Time Delay Control Device Using Liquid Crystal Beamsteerer
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Solution Overview
Problem
Current technologies face challenges in achieving controllably adjustable time delays for high-frequency light beams, particularly in phased array antennas, due to limitations in tunability, insertion loss, and integrability, with previous approaches like MEMS and optical waveguides experiencing significant losses and mechanical constraints.
Innovation Solution
An optical time delay control device using an optically transparent solid medium with mirrors and a liquid crystal waveguide beamsteerer to alter the angle of the optical beam, allowing for controllable delay without waveguide losses, enabling compact and high-resolution time delay tuning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If optical waveguides are used to achieve time delay, then the device can be integrated, but significant optical losses occur (greater than 30 dB of attenuation)
Solution Approach 1:
The patent extracts the optical beam from the waveguide structure and allows it to propagate freely through air or vacuum between mirrors. This removes the beam from the lossy waveguide environment while maintaining the ability to control path length and achieve time delay through mirror positioning and optical bench design.
Solution Approach 2:
The patent introduces an optical bench as an intermediary platform that holds mirrors and defines the optical path without confining the beam to waveguides. This intermediary structure enables precise control of light propagation paths while avoiding the attenuation problems of waveguide-based approaches.
2Loss of time
If the optical path length is increased to achieve larger time delay tunability, then the device size increases, but compactness is required for phased array antennas
Solution Approach 1:
The patent uses multiple mirrors arranged in a folded optical path configuration, allowing the light to travel a long effective distance through repeated reflections between mirrors. This folds the optical path into additional spatial dimensions, achieving large time delay tunability within a compact physical footprint suitable for phased array antenna integration.
Solution Approach 2:
The optical path is nested within itself through multiple reflections between mirrors, where the light beam traverses the same physical space multiple times in a folded configuration. This nesting of the optical path allows achieving extended time delay ranges without proportionally increasing the overall device volume.
3Ease of operation
If mechanical switches like MEMS are used, then time delay can be controlled, but mechanical constraints and reliability issues arise
Solution Approach 1:
The patent replaces mechanical switching mechanisms with an optical approach using mirrors and free-space propagation. Instead of mechanically moving switches or waveguide segments, the system uses optically controlled path length adjustment through mirror positioning, eliminating mechanical wear and improving reliability while maintaining controllability.
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 achieves delays of up to 20 nanoseconds with low insertion loss and high integrability, overcoming previous limitations by using a free-propagating beam and a compact form factor, suitable for large phased array antennas.
Implementation Method 1
a liquid crystal waveguide beamsteerer to alter the angle of the optical beam
Implementation Method 2
two mirrors affixed to two opposing parallel surfaces of the optically transparent solid medium, so that during operation the optical beam reflects between the two mirrors
Data Source
AI summary
An optical time delay control device for controllably altering the transit time of an optical beam between two points. In one example, the device may include an optically transparent solid medium for receiving the optical beam, wherein at least a portion of the medium is generally a parallel piped shape characterized by a height, length and width, wherein the length is larger than the height; two mirrors affixed to two opposing parallel surfaces of the optically transparent solid medium, so that during operation the optical beam reflects between the two mirrors as the optical beam travels through the optically transparent medium; and an angle actuator for controllably altering the angle at which the optical beam enters into the optically transparent medium, thereby controllably altering the time that the optical beam travels through the device. This in effect permits control of the amount of delay of the transmission of light, and delays of 20 nanoseconds have been achieved.