VCSEL Array Microlenses for High-Frequency Optical Communication
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Solution Overview
Problem
Existing VCSEL arrays face challenges in achieving high frequency modulation and high power output due to heating complexities, parasitic impedances, and alignment sensitivity in free space optical communication, which limits their effectiveness in applications requiring high bandwidth and reliability.
Innovation Solution
A monolithic VCSEL array device with short-circuited mesa structures and a metal heat sink configuration that reduces parasitic impedance, combined with integrated microlenses for improved heat dissipation and beam focusing, enabling high frequency response and efficient power transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If VCSEL arrays are designed for high power output, then power transmission efficiency is improved, but heating complexities and parasitic impedances increase, degrading frequency response
Solution Approach 1:
The patent divides the VCSEL array into multiple independent mesa structures, each with its own heat dissipation pathway. This segmentation allows high power output from multiple elements while distributing heat generation across separate regions, reducing thermal interference and parasitic impedance coupling between elements.
Solution Approach 2:
The patent introduces a heat sink structure as an intermediary thermal management component between the VCSEL mesas and the substrate. This heat sink acts as a thermal mediator that efficiently conducts heat away from the high-power VCSEL elements, reducing heating complexities and maintaining frequency response stability.
2Reliability
If VCSEL arrays are designed for high frequency modulation, then frequency response is improved, but power output is limited due to heating and parasitic impedances
Solution Approach 1:
By segmenting the array into multiple low-power VCSEL mesas rather than using a single high-power element, the design achieves high frequency modulation capability in each element while collectively providing high total power output. The segmentation reduces parasitic impedance effects that would limit frequency response in high-power designs.
3Measurement precision
If free space optical communication uses small spot focusing, then signal-to-noise ratio is improved, but alignment sensitivity increases, making communication difficult
Solution Approach 1:
The patent transitions from single-point focusing to array-based spatial multiplexing, where multiple VCSEL elements provide redundant optical paths. This dimensional approach to beam formation maintains signal-to-noise ratio through collective power while reducing alignment sensitivity through spatial diversity.
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 solution enhances the VCSEL array's frequency response and power output, improving reliability and efficiency in high-power applications while simplifying alignment in free space optical communication, making it suitable for high-bandwidth data transfer between mobile devices.
Implementation Method 1
Each of the VCSEL devices in the array is provided with an associated microlens
Implementation Method 2
formed of heat sink structures that improve the heat dissipation characteristics of the array
Data Source
AI summary
A VCSEL array device formed of a monolithic array of raised VCSELs on an electrical contact and raised inactive regions connected to the electrical contact. The VCSELs can be spaced symmetrically or asymmetrically, in a manner to improve power or speed, or in phase and in parallel. The raised VCSELs and raised inactive regions are positioned between the electrical contact and an electrical waveguide. The VCSELs may be separated into subarrays and each VCSEL may be covered with an integrated or bonded microlens for directing light without external lenses. The microlenses may be offset to collect or collimate light and may be shaped to form various lens profiles.