Tunable Metasurface Lidar Beam Steering
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Solution Overview
Problem
Current lidar systems face challenges in efficiently steering and focusing optical radiation for precise ranging and imaging due to limitations in beam steering and signal-to-noise ratio, particularly at varying steering angles and bandwidths.
Innovation Solution
The implementation of tunable liquid crystal metasurfaces in solid-state transceivers, which use voltage-controlled liquid crystal arrays and feedback elements like volume Bragg gratings to steer and focus optical radiation, enabling narrow beam linewidths and precise steering angles, thereby improving resolution and reducing signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional beam steering methods are used in lidar systems, then the system structure is simpler, but the beam steering precision and resolution deteriorate
Solution Approach 1:
The patent replaces mechanical beam steering components (mirrors, prisms, moving parts) with a metasurface-based optical system. The metasurface uses sub-wavelength resonant structures with spatially varying phase profiles to achieve precise beam steering and focusing without mechanical movement, thereby improving steering precision while maintaining relatively simple system structure.
Solution Approach 2:
The patent employs metasurfaces with continuously tunable phase parameters across the surface. By adjusting the phase gradient and resonance characteristics of individual meta-elements, the system achieves precise control over beam direction and focal position, enabling high-resolution steering through parameter modulation rather than mechanical reconfiguration.
2Reliability
If conventional optical components are used for focusing, then the component design is simpler, but the signal-to-noise ratio deteriorates
Solution Approach 1:
The patent utilizes composite metasurface structures combining multiple materials with different optical properties (dielectric, metallic, and resonant materials) to achieve superior focusing performance. These composite meta-elements simultaneously provide phase control, amplitude modulation, and resonance enhancement, improving signal concentration and noise rejection compared to conventional single-material optical components.
Solution Approach 2:
The patent implements spatially varying local properties across the optical component surface. Each meta-element is designed with specific local resonance characteristics and phase delays tailored to its position, enabling precise focal point control and signal concentration. This local optimization of optical properties enhances the signal-to-noise ratio by concentrating energy exactly where needed while suppressing stray light and noise.
3Measurement precision
If fixed beam width is used, then the optical system is simpler, but the resolution at varying steering angles deteriorates
Solution Approach 1:
The patent employs a dynamic metasurface system where the phase profile and beam width can be continuously adjusted based on the steering angle. By dynamically reconfiguring the phase gradient and aperture illumination across the metasurface, the system maintains constant beam width and resolution throughout the entire angular range, adapting to varying steering requirements without mechanical intervention.
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
This approach enhances the resolution and reduces noise in lidar systems by allowing precise control over optical radiation steering and focusing, leading to improved ranging and imaging capabilities.
Implementation Method 1
tunable liquid crystal metasurfaces in solid-state transceivers, which use voltage-controlled liquid crystal arrays
Implementation Method 2
voltage-controlled liquid crystal arrays to steer and focus optical radiation
Implementation Method 3
feedback elements like volume Bragg gratings to steer and focus optical radiation
Data Source
AI summary
An example optical transceiver system, such as a solid-state light detection and ranging (lidar) system, includes a tunable, optically reflective metasurface to selectively reflect incident optical radiation as transmit scan lines at transmit steering angles between a first steering angle and a second steering angle. In some embodiments, a feedback element, such as a volume Bragg grating element, may lock a laser to narrow the band of optical radiation. A receiver may include a tunable, optically reflective metasurface for receiver line-scanning or a two-dimensional array of detector elements forming a set of discrete receive scan lines. In embodiments incorporating a two-dimensional array of detector elements, receiver optics may direct optical radiation incident at each of a plurality of discrete receive steering angles to a unique subset of the discrete receive scan lines of detector elements.