Optical Depth Sensing with Polarization-Selective Metalenses
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Solution Overview
Problem
Existing optical depth sensing apparatuses face interference between multiple sensing devices when attempting to perform simultaneous depth sensing, identification, and obstacle avoidance functions, leading to reduced accuracy due to the need to reduce frame rates.
Innovation Solution
The optical depth sensing apparatus employs a configuration of first and second light sources emitting light beams with different polarization states, and corresponding first and second sensing devices equipped with metalenses that selectively transmit or reflect light based on polarization states, allowing independent measurement without interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple sensing devices are used simultaneously to perform depth sensing, identification, and obstacle avoidance functions, then the functionality and versatility of the apparatus is improved, but the sensing devices interfere with each other causing measurement precision to deteriorate
Solution Approach 1:
The patent introduces polarization state as an intermediary parameter to differentiate between multiple light sources and sensing devices. By assigning different polarization states (e.g., horizontal, vertical, circular) to different light sources, the system enables multiple sensing devices to operate simultaneously without interference, as each sensing device can selectively detect light with its corresponding polarization state
Solution Approach 2:
The patent applies local quality by making each sensing device have selective sensitivity to specific polarization states. The metalens in each sensing device is designed with specific optical properties that allow it to transmit or block light based on polarization state, creating localized functional differentiation within the system
2Measurement precision
If time sharing is used to alternate light-emitting time of different light sources to prevent interference, then the interference between sensing devices is reduced, but the frame rate is reduced and measurement time increases
Solution Approach 1:
The patent changes the parameter used for differentiation from time (time sharing) to polarization state. Instead of alternating light emission in time, multiple light sources emit simultaneously with different polarization states, allowing all sensing devices to operate at full frame rate without temporal interference
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 multiple sensing devices to operate simultaneously at the same frame rate without interference, thereby improving the accuracy and efficiency of depth sensing and related functions.
Implementation Method 1
The first light beam having the first polarization state is transmitted to the first metalens, and the second light beam having the second polarization state is reflected or absorbed by the first metalens
Data Source
AI summary
An optical depth sensing apparatus includes a first light source emitting a first light beam having a first polarization state, a second light source emitting a second light beam having a second polarization state, a first sensing device sensing the first light beam and including a first metalens, and a second sensing device sensing the second light beam and including a second metalens. An electric field direction of the first polarization state is perpendicular to an electric field direction of the second polarization state. The first light beam having the first polarization state is transmitted to the first metalens, and the second light beam having the second polarization state is reflected or absorbed by the first metalens. The second light beam having the second polarization state is transmitted to the second metalens, and the first light beam having the first polarization state is reflected or absorbed by the second metalens.