Lidar PIC Input Optics for Weak Return Signal Detection
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Solution Overview
Problem
Existing lidar systems face challenges in efficiently detecting and measuring distances to remote targets with low-power return signals, particularly in scenarios where only a small fraction of the emitted light is scattered or reflected back to the receiver.
Innovation Solution
The integration of a semiconductor optical amplifier (SOA) within the lidar system to amplify low-power return signals, combined with a photonic integrated circuit (PIC) to enhance signal detection and processing capabilities, allowing for improved distance measurement accuracy and sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the lidar system uses a conventional receiver to detect return signals, then the system structure remains simple, but the detection sensitivity is insufficient for low-power return signals from remote targets
Solution Approach 1:
The patent introduces an optical amplifier as an intermediary component between the receiver and the detector. This amplifier boosts the weak return signals before they reach the detector, thereby improving detection sensitivity without requiring a complete redesign of the receiver architecture. The amplifier acts as a mediator that enhances signal strength while maintaining the overall system structure.
Solution Approach 2:
The patent integrates the optical amplifier within the existing receiver structure, nesting it as a sub-component. This allows the amplifier to be incorporated into the conventional receiver design, improving detection capability while minimizing the increase in overall system complexity. The nested integration enables the amplifier to work in conjunction with existing receiver components.
2Measurement precision
If the lidar system emits high-power light to improve detection of remote targets, then the detection range increases, but the energy consumption increases
Solution Approach 1:
The optical amplifier serves as a mediator that allows the system to detect weak return signals from remote targets without needing to emit high-power light. By amplifying the returning signals, the system can maintain long detection ranges while using lower transmission power, thus reducing energy consumption.
Solution Approach 2:
The patent changes the parameter of signal power at the detection stage by introducing amplification. Instead of increasing the transmitted light power to improve detection range, the system maintains low transmission power and compensates by amplifying the returned signals, thereby achieving the same detection range with lower energy consumption.
3Measurement precision
If the lidar system uses only a small fraction of scattered light for detection, then the system operation is simple, but the measurement accuracy deteriorates due to low signal power
Solution Approach 1:
The optical amplifier acts as an intermediary that enhances the weak signals formed by the small fraction of scattered light. This allows the system to maintain simple operation with minimal signal collection while achieving high measurement accuracy through signal amplification before detection.
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
Enhances the detection and measurement of remote targets by amplifying weak return signals, improving the accuracy and sensitivity of distance determination in lidar systems.
Implementation Method 1
The integration of a semiconductor optical amplifier (SOA) within the lidar system to amplify low-power return signals
Data Source
AI summary
In one embodiment, a lidar system includes a light source configured to emit an optical signal and a receiver that includes one or more detectors configured to detect a portion of the emitted optical signal scattered by a target located a distance from the lidar system. The lidar system also includes a photonic integrated circuit (PIC) that includes an input optical element configured to receive the portion of the scattered optical signal and couple the portion of the scattered optical signal into an input optical waveguide. The input optical waveguide is one of one or more optical waveguides of the PIC configured to convey the portion of the scattered optical signal to the one or more detectors of the receiver. The input optical element includes a grating coupler and a tapered optical waveguide.