Integrated VCSEL Array Beam Diffusion With Sloped Lens Segments
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Solution Overview
Problem
Conventional VCSEL arrays with external diffusers suffer from sub-optimal efficiency due to divergence issues, reflection losses, and the difficulty in integrating diffusers with VCSEL arrays, particularly for applications requiring high power illumination over a specific field of view.
Innovation Solution
A bottom-emitting VCSEL chip with an integrated optical element comprising a plurality of lens segments that direct beams from VCSELs to specific angles, creating a diffusion pattern without spreading light over the entire field of view, thus mimicking the output of a conventional diffuser.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If an external diffuser is used with a VCSEL array, then light is spread over the entire field of view, but efficiency is reduced due to divergence issues and reflection losses
Solution Approach 1:
The patent merges the diffuser functionality directly into the VCSEL array structure by integrating lens segments with each VCSEL emitter. This integration eliminates the need for a separate external diffuser component, reducing optical path length and minimizing reflection losses at interfaces, thereby improving overall system efficiency while maintaining the light spreading function across the field of view.
Solution Approach 2:
The patent segments the optical element into multiple lens segments, with each lens segment corresponding to a specific VCSEL emitter. This segmentation allows each VCSEL's light to be directed independently through its associated lens segment, optimizing the diffusion pattern for each emitter and reducing unwanted divergence while maintaining energy efficiency.
2Illumination intensity
If an external diffuser is used with a VCSEL array, then light diffusion is achieved, but integration difficulty arises
Solution Approach 1:
The patent combines the diffuser function with the VCSEL array structure by integrating lens segments directly onto the VCSEL chip. This merging eliminates the need for separate alignment and assembly of an external diffuser, significantly reducing integration complexity while achieving effective light diffusion across the field of view.
Solution Approach 2:
The patent introduces lens segments as intermediary optical elements that bridge the VCSEL emitters and the field of view. These lens segments are integrated into the VCSEL array structure, serving as a mediator that simplifies the optical path and eliminates the need for complex external diffuser integration while achieving the desired light diffusion effect.
3Loss of energy
If lens segments are used to direct beams to specific angles, then divergence is reduced and efficiency is improved, but device complexity increases
Solution Approach 1:
The patent divides the optical element into multiple lens segments, with each segment corresponding to a specific VCSEL emitter. This segmentation allows for precise control of beam direction and divergence for each emitter independently. The segmented structure reduces overall device complexity compared to a single complex optical element, as each lens segment can be designed and manufactured independently using standard fabrication processes.
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 integrated optical element enhances the efficiency of the optical system by reducing divergence, minimizing reflection losses, and enabling independent illumination of different regions, achieving a higher intensity at larger angles and improving the bat-wing profile efficiency.
Implementation Method 1
a surface of a first lens segment of the plurality of lens segments is sloped to cause a beam from a first VCSEL of the plurality of VCSELs to be steered at a first angle
Data Source
AI summary
A bottom-emitting vertical-cavity surface-emitting laser (VCSEL) chip may include a VCSEL array including plurality of VCSELs and an integrated optical element including a plurality of lens segments. The integrated optical element may direct beams provided by the plurality of VCSELs to a particular range of angles to create a diffusion pattern using the beams provided by the plurality of VCSELs. A surface of a first lens segment may be sloped to cause a beam from a first VCSEL to be steered at a first angle and a surface of a second (adjacent) lens segment may be sloped to cause a beam from a second VCSEL to be steered at a second angle. A direction of the second angle with respect to a surface of the VCSEL array may be opposite to a direction of the first angle with respect to the surface of the VCSEL array.