Optical Phased Array LiDAR for Wide Field of View
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Solution Overview
Problem
Existing LiDAR systems face limitations in providing a wide field of view, high sampling rate, and high optical power handling, especially in applications like self-driving vehicles and consumer devices, due to constraints in beam steering, wavelength tunability, and power efficiency.
Innovation Solution
The LiDAR system employs an optical phased array architecture with a power splitter, amplitude or phase modulators, and emitters connected through waveguides, allowing for adaptive beam shaping and steering, wavelength selection, and encoding to achieve spatial selectivity and high throughput, using multiple lasers and encoders to optimize beam direction and power handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single laser source is used to reduce system complexity, then device complexity is reduced, but the field of view and sampling rate are limited
Solution Approach 1:
The patent divides a single laser source into multiple beam paths using optical splitters, creating multiple independent scanning channels. Each channel can be steered independently, expanding the overall field of view while maintaining a single laser source. This segmentation allows the system to achieve wide angular coverage without increasing the number of laser sources.
Solution Approach 2:
The patent introduces temporal dimension through time-division multiplexing, where multiple beams are scanned sequentially in different time slots. This allows the system to achieve high sampling rates across a wide field of view by rapidly switching between multiple beam paths, effectively adding the time dimension to the spatial scanning capability.
2Adaptability or versatility
If mechanical beam steering is used to achieve wide field of view, then field of view is improved, but the sampling rate decreases due to mechanical limitations
Solution Approach 1:
The patent replaces mechanical beam steering mechanisms with optical phased array technology, where beam direction is controlled by electronically adjusting the phase and amplitude of light at multiple emitters. This eliminates mechanical moving parts, enabling extremely fast beam switching rates (microsecond or nanosecond scale) while maintaining wide field of view coverage through phased array beamforming.
Solution Approach 2:
The patent implements dynamic beam steering by rapidly changing the phase and amplitude settings of the optical phased array elements in response to scanning requirements. This allows the beam direction to be changed instantly without mechanical inertia, achieving both wide field of view and high sampling rates through dynamic electronic control.
3Length of moving object
If high optical power is used to extend ranging distance, then ranging distance is improved, but interference and power consumption increase
Solution Approach 1:
The patent divides the total optical power into multiple lower-power beams that are transmitted sequentially through different beam paths. Each beam carries a unique encoding signature, allowing the receiver to distinguish between multiple beams. This segmentation reduces per-beam power requirements while maintaining total system power for long-range operation, and the sequential transmission reduces interference between beams.
Solution Approach 2:
The patent applies preliminary encoding to the optical signals before transmission, using unique temporal or spatial codes for each beam path. This pre-encoding allows the receiver to identify and separate signals from different beams even when they overlap in time or space, reducing interference effects and enabling coherent integration of multiple returns to extend ranging distance.
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 solution enables a scalable LiDAR system with enhanced field of view, increased sampling rate, and improved power handling, capable of efficiently imaging environments over long distances while minimizing interference and power consumption.
Implementation Method 1
an optical phased array, the optical scanner comprising: a power splitter configured to split light from a waveguide connecting to at least one laser to a plurality of waveguides; a plurality of amplitude modulators or phase modulators, each connected to the power splitter through a corresponding waveguide of the plurality of waveguides; a plurality of emitters, each emitter connected to a corresponding amplitude or phase modulator through a corresponding waveguide, wherein: the plurality of amplitude modulators or phase modulators is configured to receive control signals to control an amplitude or phase of the light, and the optical phased array is configured to emit a light beam in one or multiple spatial directions based on the amplitude or phase settings of the emitters
Data Source
AI summary
A light ranging and detection system achieving reconfigurable very wide field of view, high sampling of spatial points per second with high optical power handling by using architecture to efficiently combine different wavelengths, time and frequency coding, and spatial selectivity. The transmitter is capable of generating multiple narrow beams, encoding different beams and transmitting in different spatial directions. The receiver can differentiate and extract range and reflectivity information of reflected beams. Three dimensional imaging of the environment is achieved by scanning the field of view of the transmitter. Control and signal processing electronic circuitries fabricated in a chip are packaged together with a chip containing the photonic components of the ranging system.