Spatial Light Modulator for High-Speed LiDAR Beam Steering

Solution Overview

Problem

Current beam steering technologies in LiDAR systems for ADAS and autonomous vehicles are limited by slow beam steering speeds, which hinder the rapid detection and processing of environmental data required for advanced driving functions.

Innovation Solution

A spatial light modulator is developed, comprising a substrate with a distributed Bragg reflector, a cavity, and a grating reflector with heaters that control the refractive index to modulate light phase, enabling faster beam steering by quickly adjusting the temperature and reducing thermal crosstalk between pixels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If mechanical beam steering methods are used (rotating light source, rotating mirror, moving spherical lens), then beam steering capability is achieved, but beam steering speed is slow

Engineering Contradiction:

Improvebeam steering speedVSAvoidmechanical structure complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The patent replaces mechanical beam steering mechanisms (rotating mirrors, moving lenses) with a non-mechanical approach using a spatial light modulator that employs heaters to control the refractive index of a grating reflector, thereby steering light beams without any moving parts. This substitution of mechanical systems with thermal-optical control achieves high-speed beam steering while eliminating mechanical complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the refractive index parameter of the grating reflector material by applying heat through heaters positioned at different locations. By varying the temperature (thermal parameter), the refractive index changes, which in turn changes the phase and direction of reflected light, enabling beam steering without mechanical movement.

Inventive Principle:

Principle #35Parameter changes

2Speed

If heaters are placed directly on the grating reflector to control refractive index, then beam steering speed increases, but thermal crosstalk between pixels increases

Engineering Contradiction:

Improvebeam steering speedVSAvoidthermal crosstalk

Core Design Contradiction:

SpeedVSObject-generated harmful factors

Solution Approach 1:

The patent segments the heating function by providing separate heaters for each pixel or group of pixels rather than a single heating source. This segmentation allows independent temperature control of different regions, enabling fast beam steering while minimizing thermal crosstalk between adjacent pixels through spatial separation of heat sources.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a spacer layer as an intermediary between the heaters and the grating reflector. This spacer layer acts as a thermal barrier that reduces direct heat transfer to the grating reflector and minimizes thermal crosstalk between adjacent heated regions, while still allowing the refractive index to be controlled for beam steering purposes.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If beam steering speed is increased for rapid scanning, then data acquisition efficiency improves, but thermal crosstalk between pixels increases

Engineering Contradiction:

Improvedata acquisition efficiencyVSAvoidthermal crosstalk

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent segments the heating function by providing separate heaters for each pixel or group of pixels rather than a single heating source. This segmentation allows independent temperature control of different regions, enabling fast beam steering while minimizing thermal crosstalk between adjacent pixels through spatial separation of heat sources.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a spacer layer as an intermediary between the heaters and the grating reflector. This spacer layer acts as a thermal barrier that reduces direct heat transfer to the grating reflector and minimizes thermal crosstalk between adjacent heated regions, while still allowing the refractive index to be controlled for beam steering purposes.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 increases beam steering speed, enhancing the accuracy and efficiency of light direction control, thereby improving the performance of LiDAR systems in vehicles and other applications by allowing for rapid scanning and data acquisition.

Implementation Method 1

a refractive index of the grating reflector is controlled by heat supplied from a corresponding heater

Methodology Applied

Scientific EffectThermal control of refractive index: Temperature Gradient

Implementation Method 2

a distributed Bragg reflector provided on the substrate

Methodology Applied

Scientific EffectBragg reflection: Bragg Diffraction

Implementation Method 3

a refractive index of the grating reflector is controlled by heat supplied from a corresponding heater

Methodology Applied

Scientific EffectThermo-optic effect: Temperature Gradient

Data Source

PatentUS11287516B2Spatial light modulator and beam steering apparatus including the same

Publication Date: 2022.03.29 SAMSUNG ELECTRONICS CO LTD

AI summary

A spatial light modulator and a beam steering apparatus including the same are provided. The spatial light modulator may include a distributed Bragg reflector provided on a substrate, a cavity provided on the distributed Bragg reflector, a grating reflector provided on the cavity, and a heater provided on the grating reflector.