Optical Phased Array Beam Steering for 3D ToF Illumination
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Solution Overview
Problem
Current light emission apparatuses for time-of-flight image systems face challenges in dynamically adjusting illumination angles and achieving compact size for 3D target scanning, while also ensuring eye-safety and efficient power consumption.
Innovation Solution
The light emission apparatus employs an optical phase array transmitter with a grating coupler array and phase shifters to dynamically adjust the illumination angle and divergence, incorporating edge-emitting or vertical emitting lasers with optical elements for efficient scanning and wavelength conversion, and includes mechanisms for eye-safety and power management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional light emission apparatus is used, then the structure is simple, but the illumination angle cannot be dynamically adjusted for 3D target scanning
Solution Approach 1:
The patent implements dynamic illumination angle adjustment by integrating a grating coupler array with phase shifters that can be electrically controlled to change the phase of light waves, enabling the beam direction to be dynamically steered without mechanical moving parts. This resolves the contradiction by making the optical system adaptable while maintaining a fixed, compact structure.
Solution Approach 2:
The patent introduces an optical phase array transmitter as an intermediary component between the laser source and the target. This intermediary uses grating couplers and phase shifters to control and redirect light paths, enabling angle adjustment functionality without requiring complex mechanical scanning systems.
2Adaptability or versatility
If multiple optical components are added for angle adjustment, then the illumination angle can be dynamically adjusted, but the device size increases
Solution Approach 1:
The patent integrates multiple optical functions (laser emission, phase modulation, beam steering) into a nested hierarchical structure where the grating coupler array and phase shifters are implemented on a single photonic integrated circuit chip. This nesting approach allows complex optical functionality to be achieved within a compact footprint, resolving the contradiction between adaptability and device size.
Solution Approach 2:
The patent merges multiple optical components (laser diodes, phase shifters, grating couplers) into a single integrated optical module on a photonic chip. This consolidation achieves dynamic angle adjustment functionality while minimizing the overall device volume by eliminating the need for separate mechanical scanning components.
3Measurement precision
If high power laser is used for better signal quality, then the signal-to-noise ratio improves, but eye-safety becomes a concern
Solution Approach 1:
The patent employs periodic pulsed laser operation instead of continuous wave emission. By delivering light in short, high-intensity pulses, the system achieves the necessary signal-to-noise ratio for accurate depth measurement while keeping the average power low enough to ensure eye safety. This periodic action resolves the contradiction between measurement precision and harmful effects.
Solution Approach 2:
The patent changes the temporal parameters of light emission from continuous to pulsed mode, and adjusts the pulse width and repetition rate to optimize both signal quality and eye safety. This parameter change allows the system to achieve high peak power for good signal-to-noise ratio while maintaining low average power for eye safety compliance.
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 efficient scanning of 3D targets with improved signal-to-noise ratio, reduced power consumption, and compact design, while ensuring eye-safety through dynamic illumination adjustments and wavelength conversion.
Implementation Method 1
an optical phase array transmitter with a grating coupler array and phase shifters to dynamically adjust the illumination angle and divergence
Implementation Method 2
an optical phase array transmitter with a grating coupler array and phase shifters to dynamically adjust the illumination angle and divergence
Implementation Method 3
incorporating edge-emitting or vertical emitting lasers with optical elements for efficient scanning and wavelength conversion
Implementation Method 4
incorporating edge-emitting or vertical emitting lasers with optical elements for efficient scanning and wavelength conversion
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
A light emission apparatus includes a laser diode configured to emit a light; a laser driver electrically coupled to the laser diode, the laser driver being configured to drive the laser diode to generate the light; and an optical module arranged to receive the light emitted by the laser diode, the optical module comprising at least one optical element and being configured to adjust the light and emits a transmitting light; wherein the transmitting light emits from the optical module with an illumination angle and the optical module adjusts the light to vary the illumination angle.