Frequency-Modulated LiDAR with SPPR for 360° Scanning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LIDAR systems face challenges in achieving a full 0 to 360° scanning range without movable parts, which are prone to mechanical failure and limited by mechanical speed and wear, while existing optical solutions like MEMS and liquid crystal scanners have limited scanning FOV and ranging distance.
Innovation Solution
A LIDAR system utilizing a spiral phase plate resonator (SPPR) device with a frequency modulated laser beam that is directed through a conical mirror to achieve a 360° FOV, compensating for temperature changes and employing coherent superposition of optical vortices to determine distance and velocity without mechanical components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If movable mechanical components are used to scan the light beam, then the scanning FOV can be achieved, but the system reliability decreases due to mechanical failure risk and wear
Solution Approach 1:
The patent replaces mechanical scanning components (mirrors, gimbals, motors) with an acoustic field-based optical phase modulation system. Acoustic waves modulate the refractive index of the medium, creating dynamic optical paths that steer the beam without physical movement, thereby eliminating mechanical wear and failure risks while maintaining full 360° scanning capability
Solution Approach 2:
The patent employs periodic acoustic waves to create time-varying refractive index distributions that periodically modulate the optical phase. This periodic action enables continuous beam scanning across the full FOV by cycling through different acoustic excitation patterns, achieving sustained operation without mechanical fatigue
2Ease of operation
If mechanical components are used for beam scanning, then the scanning function is achieved, but the scanning speed is limited by mechanical rotation speed
Solution Approach 1:
The patent substitutes mechanical rotation with acoustic wave propagation. Acoustic waves can be modulated at frequencies much higher than mechanical systems, enabling rapid beam steering and significantly increasing scanning speed while maintaining full FOV coverage capability
3Area of stationary object
If multiple LIDAR systems are combined to cover full 0 to 360° FOV, then the scanning coverage is improved, but the device complexity increases
Solution Approach 1:
The patent creates a single LIDAR system that performs multiple scanning functions (azimuth and elevation) through acoustic field modulation. The acoustic medium serves as a universal beam steering mechanism that can direct the beam to any angle in 3D space, replacing the need for multiple specialized LIDAR units while reducing overall system complexity
Solution Approach 2:
The patent merges azimuth and elevation scanning functions into a single integrated system using acoustic phase modulation. By combining multiple acoustic transducers and coordinating their outputs, the system achieves full 3D beam steering capability in one unified apparatus rather than requiring separate systems for each scanning dimension
4Productivity
If MEMS devices are used for beam scanning, then the scanning frequency is increased, but the scanning FOV is limited
Solution Approach 1:
The patent transitions from the limited angular deflection of MEMS mirrors to a three-dimensional acoustic field distribution that can modulate optical paths in multiple directions simultaneously. This dimensional expansion of the control space enables both high-frequency operation and full 360° FOV coverage by exploiting the volumetric nature of acoustic wave propagation
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 provides a compact, resilient, and high-power-tolerant solution for instantaneous 360° scanning with precise distance and velocity measurement, overcoming mechanical limitations and achieving long-range scanning without mechanical wear.
Implementation Method 1
a coherent superposition of optical vortices can be generated by either reflecting light off of the device or transmitting light through the device
Implementation Method 2
employing a spiral phase plate resonator (SPPR) device... having a spiral step index that causes multiple internal reflected beams having different phases to be combined
Implementation Method 3
shifts the frequency of the laser beam to a second frequency to change the angle that the transmitted beam is directed from the conical mirror
Implementation Method 4
the time of flight of the beam is used to determine the distance to the target
Implementation Method 5
determines a temperature of optical and electro-optical components in the transmitter and/or receiver sub-systems, and adjusts the first frequency of the laser beam to compensate for changes in the temperature
Data Source
Figure 1~3
Figure 4~7
Figure 5
AI summary
A method for scanning a transmitted beam through a 360° FOV in a LIDAR system using no moving parts. The method includes generating a laser beam, frequency modulating the laser beam, and directing the frequency modulated laser beam to a spiral phase plate resonator (SPPR) device. The method further includes directing the beam from the SPPR device onto a conical mirror, and receiving a reflected beam from the target. The method mixes and correlates the transmitted beam and the reflected beam, calculates a fast Fourier transform of signals representing the mixed transmitted and reflected beams, determines beat frequencies in the mixed and transformed signals, identifies intermediate frequencies in the beat frequencies, estimates a time delay between the transmitted beam and the reflected beam from the beat frequencies to determine the distance to the target, and determines a Doppler frequency from the beat frequencies to determine the velocity of the target.