Silicon Nitride Waveguide Optical Phased Array Lidar
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Solution Overview
Problem
Existing silicon-based optical phased array chips are limited to wavelengths larger than 1100 nm and cannot operate within the visible light band, restricting their application range.
Innovation Solution
An optical phased array lidar system that includes a laser, an optical beam splitter, a phase controller, a silicon nitride waveguide array, and an optical antenna array based on a one-dimensional grating structure, which enables the transmission of near-infrared light and visible light by regulating the phases of sub-signals and scattering them into free space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If silicon-based optical phased array chip is used, then all-solid-state lidar is achieved, but working wavelength is limited to larger than 1100 nm and cannot work within visible light band
Solution Approach 1:
The patent uses silicon nitride material instead of conventional silicon material for the optical phased array chip. Silicon nitride has different optical properties that enable it to transmit both near-infrared light ( >1100 nm) and visible light (400-700 nm), thus expanding the working wavelength range while maintaining the all-solid-state lidar functionality.
Solution Approach 2:
The patent changes the material parameter from silicon to silicon nitride, which fundamentally alters the optical transmission characteristics. This material substitution enables the chip to operate across a broader spectrum including visible light, resolving the wavelength limitation of conventional silicon-based devices.
2Ease of operation
If mechanical rotation is used for beam scanning, then lidar scanning is achieved, but large volume and power consumption occur
Solution Approach 1:
The patent replaces mechanical rotation with an all-solid-state optical phased array system that uses electronic phase control to achieve beam scanning. The phase controller adjusts the phase of light waves electronically through the silicon nitride waveguide array, eliminating the need for mechanical moving parts and significantly reducing system volume and power consumption while maintaining beam scanning capability.
3Ease of operation
If microelectromechanical systems lidar is used, then small scanning angle is achieved, but sensitivity to vibrations occurs
Solution Approach 1:
The patent replaces microelectromechanical systems with an all-solid-state optical phased array system. The beam scanning is achieved through electronic phase modulation in the silicon nitride waveguide array rather than mechanical movement, completely eliminating sensitivity to vibrations while maintaining compact scanning angles.
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 effectively broadens its working range to include visible light, enabling light spot scanning and overcoming the limitations of previous silicon-based optical phased array chips.
Implementation Method 1
an optical beam splitter, configured to split the laser signal to obtain multiple sub-signals, and distribute the multiple sub-signals to respective optical paths
Implementation Method 2
a phase controller, connected to the optical beam splitter and configured to regulate phases of the multiple sub-signals
Implementation Method 3
a silicon nitride waveguide array, configured to transmit the multiple sub-signals and the phase-regulated sub-signals
Implementation Method 4
an optical antenna array based on a one-dimensional grating structure, connected to the phase controller and configured to uniformly scatter the phase-regulated sub-signals into free space
Implementation Method 5
the electrical controller includes micro heaters configured to regulate temperatures of the first silicon nitride waveguides
Data Source
AI summary
An optical phased array lidar includes: a laser, for emitting a laser signal; an optical beam splitter, for splitting a laser signal into multiple sub-signals, and distributing them to corresponding optical paths; a phase controller connected to the optical beam splitter, for regulating phases of the multiple sub-signals; an optical antenna array based on a one-dimensional grating structure, connected to the phase controller and for uniformly scattering the phase-regulated sub-signals into free space; and a silicon nitride waveguide array, for transmitting the sub-signals and phase-regulated sub-signals to realize the transmission of near-infrared light and visible light. The optical phased array lidar uses a silicon nitride waveguide array for transmission, thereby realizing the transmission of near-infrared light and visible light. In this way, the lidar can work in the visible light band, thereby broadening the working ranging thereof.