Multi-Layer LiDAR Chip Segmentation for Nonlinear Loss
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Solution Overview
Problem
Current phased array LiDAR chips using silicon substrates face limitations due to silicon's strong nonlinearity and absorption effects, restricting high-power light transmission and affecting detection performance.
Innovation Solution
A phased array LiDAR transmitting chip with a multi-layer structure, incorporating a first material layer with a lower nonlinear refractive index than silicon, coupled with an SOI silicon waveguide structure, enables increased optical power input by using an input coupler and beam splitter to split light waves, allowing them to transmit effectively through silicon waveguides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If silicon material is used in phased array LiDAR chips, then basic LiDAR functions can be realized, but high-power light transmission is restricted due to strong nonlinearity and absorption effects
Solution Approach 1:
The patent divides the optical path into two segments: a first material structure layer with low nonlinear refractive index for high-power light transmission, and an SOI silicon waveguide structure layer for signal processing. This segmentation allows each layer to perform its optimal function without the harmful nonlinear effects limiting overall power transmission.
Solution Approach 2:
The first material structure layer acts as an intermediary between the light source and the silicon waveguide structure. It couples high-power input light to the chip and distributes it through beam splitters to multiple silicon waveguides, enabling high-power transmission while the silicon layer handles signal processing at reduced power levels.
2Power
If high-power light is transmitted in silicon waveguide, then optical power input can be increased, but loss increases due to strong two-photon absorption and free carrier absorption
Solution Approach 1:
The optical transmission path is segmented into two functional layers: the first material structure layer handles high-power transmission with minimal loss, while the silicon waveguide layer performs signal processing. This division prevents high-power light from causing excessive two-photon absorption in the silicon waveguides.
Solution Approach 2:
Different regions of the chip have different material properties optimized for their specific functions. The first material structure layer is designed with low nonlinear refractive index for high-power transmission, while the silicon waveguide layer is optimized for signal processing. This local optimization ensures minimal energy loss in the transmission path.
3Reliability
If silicon substrate is used, then basic LiDAR functions are achieved, but detection performance is seriously affected due to low-order nonlinear refractive index
Solution Approach 1:
The chip is segmented into two functional layers: the first material structure layer with low nonlinear refractive index for optical transmission, and the silicon waveguide layer for signal processing. This segmentation isolates the harmful nonlinear refractive effects to the transmission layer while maintaining reliable detection performance in the processing layer.
Solution Approach 2:
The first material structure layer serves as an intermediary that couples light to the chip and distributes it through beam splitters to multiple silicon waveguides. This intermediary layer with its low nonlinear refractive index protects the detection system from power-induced nonlinear effects, ensuring stable detection performance.
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 significantly enhances the optical power input to the LiDAR chip, improving detection performance and reducing pressure on signal detection, while minimizing absorption effects.
Implementation Method 1
the input coupler is configured to couple input light to the chip
Implementation Method 2
the beam splitter is configured to split a light wave coupled to the chip
Implementation Method 3
an overlapping region of a rear end of the first material structure layer and a front end of the SOI silicon waveguide structure layer forms a coupling connection structure
Implementation Method 4
each of the phase modulators is configured to change a phase of a light wave coupled to a corresponding silicon waveguide
Implementation Method 5
the optical antenna is configured to transmit phase-changed light waves in silicon waveguides into space
Implementation Method 6
silicon is a strongly nonlinear material with a strong two-photon absorption effect
Implementation Method 7
a free carrier absorption effect
Data Source
AI summary
A phased array LiDAR transmitting chip of multi-layer materials includes: a first material structure layer and an SOI silicon waveguide structure layer, a rear end of the first material structure layer and a front end of the SOI silicon waveguide structure layer form a coupling connection structure. The first material structure layer includes an input coupler and a beam splitter. The input coupler is optically connected to the beam splitter. The beam splitter is optically connected to the SOI silicon waveguide structure layer through the coupling connection structure. The input coupler couples input light to the chip. The beam splitter split a light wave coupled to the chip. The coupling connection structure couples each split light wave to a silicon waveguide in the SOI silicon waveguide structure layer. A non-linear refractive index of a first material in the first material structure layer is lower than that of a silicon material.