Free-Space Reference Light Unit Cell for Precise Optical Detection
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Solution Overview
Problem
Existing waveguide systems for light transmission and reception induce significant optical losses and require large areas for lateral guidance, complicating accurate detection of light from a target.
Innovation Solution
A unit cell design that emits coherent light into free space, extracts reference light using an extractor, and integrates a photo-sensitive element to simultaneously detect target and reference light, eliminating waveguide-induced losses and enabling a compact, vibration-resistant arrangement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If waveguide systems are used for guiding light, then transmission of reference light can be accurately controlled, but significant optical losses are induced and large area is required
Solution Approach 1:
The patent extracts the reference light from the waveguide system and allows it to propagate through free space directly to the photo-sensitive element. This removes the reference light path from the waveguide, eliminating the optical losses associated with waveguide propagation while maintaining the ability to control the reference light through the extractor positioning
Solution Approach 2:
The patent segments the optical path into two distinct parts: the measurement light path that travels to the target and returns, and the reference light path that is extracted and propagated through free space. This segmentation allows each path to be optimized independently, with the reference path avoiding waveguide losses
2Measurement precision
If waveguide systems are used for guiding light, then transmission of reference light can be accurately controlled, but large area is required for lateral guidance
Solution Approach 1:
The patent transitions the reference light propagation from a lateral waveguide path (2D plane) to a free space path (3D space). By allowing the reference light to propagate through the third dimension (free space above the substrate), the device achieves accurate reference light delivery without requiring extensive lateral area
3Area of stationary object
If light emitting unit and photo-sensitive element are arranged close to each other, then compact arrangement is achieved, but precise alignment is required
Solution Approach 1:
The extractor serves as an intermediary element that precisely controls the extraction and direction of reference light to the photo-sensitive element. This intermediary component enables accurate alignment between the light emitting unit and photo-sensitive element by mediating the reference light path, allowing compact arrangement without sacrificing alignment precision
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 unit cell achieves high-efficiency light detection with minimal power consumption, avoiding parallax errors and optical losses, and allows for a compact, densely packed array suitable for precise ranging and data communication.
Implementation Method 1
a light emitting unit configured to emit coherent light
Implementation Method 2
the light from the target and the reference light are provided simultaneously in the photo-sensitive element such that a relation between the light from the target and the reference light may be detected directly in the photo-sensitive element as an interference of the light from the target with the reference light
Implementation Method 3
at least one photo-sensitive element, each configured to receive the light from the target based on emitted coherent light and to receive reference light from the extractor
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A unit cell (100; 200; 300) for detection of light from a target comprises: a light emitting unit (110; 210; 310) for emitting coherent light towards the target; an extractor (120; 220; 320) for extracting part of the emitted coherent light to form reference light; at least one photo-sensitive element (130, 132; 230a-h; 330, 332), each configured to receive light from the target based on emitted coherent light and to receive reference light for detecting both light from the target and reference light; wherein the unit cell (100; 200; 300) defines an optical path for reference light between the extractor (120; 220; 320) and the photo-sensitive element(s) (130, 132; 230a-h; 330, 332), wherein the reference light propagates through the optical path according to a free space propagation model; wherein the extractor (120; 220; 320) is, at least during a measurement, fixed in relation to the photo-sensitive element(s) (130, 132; 230a-h; 330, 332).