VCSEL Array Resistance Layout for Long-Distance Ranging Accuracy
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Solution Overview
Problem
Current ranging methods using vertical-cavity surface-emitting laser elements face accuracy issues due to low light-receiving sensitivity for oblique light angles, particularly in long-distance measurements, affecting the accuracy of surrounding region measurements.
Innovation Solution
A light-emitting element with a vertical-cavity surface-emitting laser structure, featuring a central and surrounding region configuration with varying electrical resistance and light-emission intensity distribution, where the surrounding region has a higher light-emission intensity to compensate for reduced sensitivity, achieved through controlled current path resistance and light extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a diffusion plate is used to diffuse light from multiple light emitters, then short-distance measurement is achieved, but long-distance measurement capability is lost
Solution Approach 1:
The patent applies local quality by creating different light emission intensities for different regions of the light emitter array. The central region emits light with a first intensity while the surrounding region emits light with a second intensity that is higher than the first intensity. This non-uniform intensity distribution compensates for the detector's reduced sensitivity to oblique light angles, enabling both short and long-distance measurements with improved accuracy.
2Adaptability or versatility
If light is emitted in a beam formation suitable for long-distance measurement, then long-distance measurement is achieved, but measurement accuracy for surrounding regions is reduced due to low light-receiving sensitivity for oblique angles
Solution Approach 1:
The patent applies local quality by creating different light emission intensities for different regions of the light emitter array. The central region emits light with a first intensity while the surrounding region emits light with a second intensity that is higher than the first intensity. This non-uniform intensity distribution compensates for the detector's reduced sensitivity to oblique light angles, enabling both short and long-distance measurements with improved accuracy.
3Ease of manufacture
If uniform light emission intensity is used across all light emitters, then manufacturing is simplified, but measurement accuracy for surrounding regions is reduced
Solution Approach 1:
The patent applies local quality by creating different light emission intensities for different regions of the light emitter array. The central region emits light with a first intensity while the surrounding region emits light with a second intensity that is higher than the first intensity. This non-uniform intensity distribution compensates for the detector's reduced sensitivity to oblique light angles, enabling both short and long-distance measurements with improved accuracy.
Solution Approach 2:
The patent applies parameter changes by varying the light emission intensity parameter across different regions of the light emitter array. Specifically, the light emitters in the surrounding region are configured to emit light with a second intensity that is higher than the first intensity of the central region. This parameter variation compensates for the detector's angular sensitivity characteristics and improves ranging accuracy for surrounding regions.
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
Enhances the accuracy of long-distance ranging by improving light-receiving sensitivity for oblique light angles, preventing reductions in accuracy for surrounding region measurements without increasing component costs or size.
Implementation Method 1
each of the plurality of light emitters being a vertical-cavity surface-emitting laser element, each of the plurality of light emitters including a first electrode and a second electrode, each of the plurality of light emitters emitting the light due to current flowing from the first electrode to the second electrode
Implementation Method 2
an active layer that is arranged between the first DBR layer and the second DBR layer, and emits light due to current on which confinement has been performed by the current confinement layer
Implementation Method 3
Each of the plurality of light emitters may include a first distributed Bragg reflector (DBR) layer that is electrically connected to the first electrode; a second DBR layer that is electrically connected to the second electrode
Data Source
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AI summary
[Object] To provide a light-emitting element that has a vertical-cavity surface-emitting laser structure and is suitable for a long-distance light irradiation, and a ranging apparatus. [Solving Means] A light-emitting element according to the present technology includes a plurality of light emitters, a first electrode terminal, and a second electrode terminal. The plurality of light emitters is a plurality of light emitters one-dimensionally or two-dimensionally arranged in a direction that is vertical to an optical axis corresponding to light that exits each of the plurality of light emitters, each of the plurality of light emitters being a vertical-cavity surface-emitting laser element, each of the plurality of light emitters including a first electrode and a second electrode, each of the plurality of light emitters emitting the light due to current flowing from the first electrode to the second electrode. The first electrode terminal is electrically connected to the first electrode. The second electrode terminal is electrically connected to the second electrode. A current path from the first electrode terminal to the second electrode terminal that passes through one of the plurality of light emitters exhibits an electrical resistance different from an electrical resistance of a current path from the first electrode terminal to the second electrode terminal that passes through another of the plurality of light emitters.