Acousto-Optic Modulator LIDAR Beam Steering
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Solution Overview
Problem
Conventional LIDAR systems rely on complex mechanical subsystems that are costly, susceptible to vibrations, and have limited scanning speed due to inertia, making them unsuitable for many applications that require high accuracy and low power consumption.
Innovation Solution
A solid-state LIDAR system utilizing electrically controllable light-direction-changing elements, such as MEMS devices or nematic liquid crystals, to generate successive diffraction grating patterns that move intensity maxima across a field of view, allowing for precise control of light direction without mechanical moving parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If mechanical subsystems with rotating and/or tilting mirrors are used to move the laser beam across the field of view, then the LIDAR system can achieve beam scanning capability, but the system becomes large, expensive, and susceptible to vibrations with limited scanning speed
Solution Approach 1:
The patent replaces mechanical mirror scanning systems with an acousto-optic modulator (AOM) that uses sound waves to diffract and steer the laser beam. The AOM uses acoustic energy instead of mechanical movement to achieve beam direction control, eliminating rotating/tilting mirrors and their associated inertia, vibrations, and mechanical complexity while enabling faster scanning speeds.
Solution Approach 2:
The patent changes the operating parameters by using acoustic frequency modulation in the AOM to control beam direction. By varying the acoustic frequency and amplitude, the system can dynamically adjust the diffraction angle and beam position without any mechanical movement, achieving rapid scanning through electrical parameter changes rather than mechanical motion.
2Measurement precision
If mechanical subsystems are built to relatively high tolerances to improve accuracy, then measurement precision improves, but manufacturing cost increases
Solution Approach 1:
The patent eliminates the need for precision-machined mechanical components by replacing the mechanical mirror system with an acousto-optic modulator. The AOM achieves beam steering through acoustic wave modulation in a crystal or glass medium, which can be manufactured with standard tolerances. The precision is achieved through electrical control of acoustic parameters rather than mechanical tolerance, significantly reducing manufacturing costs while maintaining or improving accuracy.
3Adaptability or versatility
If mechanical subsystems are used for beam scanning, then the system can cover a field of view, but the power requirements become relatively high
Solution Approach 1:
The patent replaces power-hungry mechanical motors and actuators with an acousto-optic modulator that uses electrical signals to generate acoustic waves for beam steering. The AOM consumes significantly less power because it uses electromagnetic-to-acoustic energy conversion in a stationary medium rather than driving mechanical components against friction and inertia, while still achieving comprehensive field of view coverage through rapid acoustic modulation.
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 system achieves a low-cost, low-power, and reliable LIDAR solution with improved scanning speed and accuracy, suitable for various applications including obstacle detection, topographical mapping, and atmospheric sensing.
Implementation Method 1
The AOM 303 uses acoustic waves to diffract the laser beam 302
Implementation Method 2
an acousto-optic modulator (AOM) 303 that uses acoustic waves to diffract the laser beam
Data Source
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AI summary
Solid-state electronic light detection and ranging (LIDAR) is disclosed. In one aspect, an electronic device for use in a LIDAR system is provided. The electronic device includes a plurality of electrically controllable light-direction-changing elements. The electronic device is configured to receive, from a laser, a beam of light. The electronic device also receives, from a controller, a series of signals that control the electrically controllable light-direction-changing elements to generate a successive series of different diffraction grating patterns configured to move at least one intensity maxima to a corresponding successive series of locations across a field of view (FOV).