Chip-Scale LiDAR Free-Space Coupling for Longer Detection Range
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Solution Overview
Problem
Lidar systems using photonic chips experience power losses at internal waveguides and edge couplers, limiting the detectable range of objects.
Innovation Solution
A Lidar system that generates a light beam without substantial power loss by using a photonic chip with a laser, a microelectromechanical (MEMS) scanner, and a free space circulator, where the transmitted light beam is directed into free space and the reflected light beam interferes with a local oscillator beam to determine object parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If light passes through internal waveguide and edge coupler in photonic chip, then light can be transmitted and received, but power losses occur at waveguide and edge coupler reducing detectable range
Solution Approach 1:
The patent extracts the laser source from the internal photonic chip structure and positions it at the front facet, allowing direct coupling to free space through the first aperture. This eliminates the need for light to pass through internal waveguides and edge couplers, thereby removing the source of power losses while maintaining the chip-scale integrated architecture.
Solution Approach 2:
The patent introduces a free space circulator as an intermediary component that enables bidirectional light path management. The circulator directs transmitted light from the first aperture to the MEMS scanner and directs reflected light from the MEMS scanner to the second aperture, allowing separate transmission and reception paths without requiring internal waveguide coupling.
2Loss of energy
If laser is integrated into photonic chip with front facet at aperture, then light beam can be directed into free space without substantial power loss, but device structure becomes more complex
Solution Approach 1:
The photonic chip is designed to perform multiple functions: it integrates the laser source, provides structural support for the MEMS scanner, houses the free space circulator, and enables both transmission and reception functions through its apertures. This multi-functionality consolidates what would otherwise require separate components, managing the added complexity through functional integration.
Solution Approach 2:
The patent implements a nested structure where the MEMS scanner is positioned within the photonic chip assembly, the free space circulator is integrated into the chip structure, and the laser is embedded at the front facet. This nesting approach allows compact arrangement of multiple functional elements within the chip-scale form factor, organizing complexity in a hierarchical manner.
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 navigates vehicles by accurately determining object parameters such as range, azimuth, and velocity with reduced power loss, enhancing the detectable range and accuracy of object detection.
Implementation Method 1
generating a transmitted light beam at a photonic chip via a laser at the photonic chip
Implementation Method 2
The reflected light beam and the local oscillator beam interfere with each other within the photonic chip
Data Source
AI summary
A vehicle, Lidar system and method of detecting an object is disclosed. The Lidar system includes a photonic chip, and a laser integrated into the photonic chip. The laser has a front facet located at a first aperture of the photonic chip to direct a transmitted light beam into free space. A reflected light beam that is a reflection of the transmitted light beam is received at the photonic chip and a parameter of the object is determined from a comparison of the transmitted light beam and the reflected light beam. A navigation system operates the vehicle with respect to the object based on a parameter of the object.