Optical-Electro System for Lidar Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current Lidar technologies, particularly TOF Flash Lidar, face challenges with noise susceptibility and limited long-distance signal detection due to the weakness of returned pulses and wide bandwidth detection electronics, leading to errors in measurement and restricted range.
Innovation Solution
An optical-electro system integrating multiple photodetectors on a chip using Frequency Modulated Continuous Wave (FMCW) technology, where a reflected signal light and coherent local light are inputted to generate interfered signals, reducing noise and enabling long-distance detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If TOF Flash Lidar uses a single light source to illuminate the field of view in a single pulse, then the acquisition speed of 3-D images is improved, but the system becomes susceptible to noise due to the weakness of returned pulses and wide bandwidth of detection electronics
Solution Approach 1:
The patent changes the detection parameter from direct pulse detection to beat frequency detection. By using FMCW modulation and detecting the beat frequency between local and returned light, the system transforms the weak pulse signal into a measurable frequency difference, thereby reducing noise susceptibility while maintaining high acquisition speed
Solution Approach 2:
The patent introduces a local light wave as an intermediary reference signal. This local light mixes with the returned light in the photodetector, creating beat frequency signals that are easier to detect and process, thereby reducing the direct impact of noise on measurement accuracy
2Device complexity
If TOF Flash Lidar uses threshold triggering to detect returned pulses, then the detection process is simplified, but measurement errors occur in Δt due to noise and weakness of returned pulses
Solution Approach 1:
The patent replaces the mechanical/electronic threshold triggering method with an optical mixing method. Instead of directly detecting weak pulses and using threshold triggering, the system mixes returned light with local light to create beat frequency signals, which are then detected electronically with much higher precision and immunity to noise
Solution Approach 2:
The patent changes the detection parameter from direct time difference measurement to beat frequency measurement. This parameter transformation allows for more precise measurements because frequency detection is less susceptible to noise and signal weakness compared to direct pulse timing
3Adaptability or versatility
If traditional Lidar uses rotation parts to scan laser beams through the field of view, then the laser beams can cover the entire field of view, but the speed of acquiring 3-D images becomes slow
Solution Approach 1:
The patent extracts and eliminates the mechanical rotation part from the Lidar system. By using a single light source that illuminates the entire field of view simultaneously and detecting returned light from multiple positions through a single aperture, the system achieves full field of view coverage without mechanical scanning, thereby dramatically increasing acquisition speed
Solution Approach 2:
The patent transitions from a temporal scanning approach (scanning beam over time) to a spatial parallel detection approach (detecting light from multiple positions simultaneously). This dimensional change from sequential to parallel processing enables high acquisition speed while maintaining complete field of view coverage
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 robust long-distance signal detection with minimal noise, allowing for faster acquisition of 3-D images and higher data rates compared to traditional Lidars, thanks to its solid-state design and integrated photodetectors.
Implementation Method 1
the optical coupling unit couples the local light and the signal light to generate a first interfered light and a second interfered light
Implementation Method 2
a first photodetector to receive the first interfered light and convert the first interfered light into a first current
Data Source
AI summary
The present application relates to an optical-electro system, which includes a substrate; at least one photo-detecting unit at least partially formed on the substrate to detect a signal light; at least one optical waveguide at least partially formed on the substrate, each of the at least one optical waveguide connected to one of the at least one photo-detecting unit to input a local light; and at least one electronic output port connected to the at least one photo-detecting unit to transmit at least one electronic output signal from the at least one photo-detecting unit, wherein the at least one electronic output signal is associated with the signal light and the local light.