VCSEL With Aperture Substrate for Heat Dissipation and Broad Wavelengths

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

High-power edge-emitting Fabry-Perot lasers are prone to catastrophic failures due to high optical power density and have high manufacturing costs, while traditional VCSELs face limitations in heat dissipation and wavelength transparency, particularly in 'top-emission' types and substrate-dependent wavelength limitations in 'bottom-emission' types.

Innovation Solution

A VCSEL design incorporating a substrate with an aperture for light emission, featuring an opaque bottom layer for heat dissipation and allowing propagation of various wavelengths, along with a ball lens for precise alignment and improved manufacturing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If light propagates through the substrate in bottom-emission VCSELs, then heat dissipation is improved, but wavelength range is limited by substrate transparency

Engineering Contradiction:

Improveheat dissipationVSAvoidwavelength range

Core Design Contradiction:

TemperatureVSAdaptability or versatility

Solution Approach 1:

The substrate is segmented by introducing an aperture that divides it into a solid portion and an empty opening. This allows the light emission path to be separated from the substrate material, enabling heat dissipation through the substrate while eliminating wavelength restrictions imposed by substrate transparency requirements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The aperture extracts or removes a portion of the substrate material from the light emission path. This extraction allows light to escape through the opening without being constrained by the substrate's optical transparency properties, thereby expanding the usable wavelength range while maintaining the substrate's heat dissipation function.

Inventive Principle:

Principle #2Taking out (Extraction)

2Ease of manufacture

If optical power is concentrated at the light emitting facet in edge-emitting FP lasers, then manufacturing cost is reduced, but device reliability deteriorates due to catastrophic failures

Engineering Contradiction:

Improvemanufacturing costVSAvoiddevice reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The invention transitions from edge-emitting geometry to vertical cavity surface-emitting geometry, changing the dimensional orientation of light emission. This vertical configuration distributes optical power density over a larger lateral surface area at the emitting facet, improving reliability while maintaining manufacturing feasibility through standard VCSEL fabrication processes.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Productivity

If multiple VCSELs are tested at wafer level, then productivity is improved, but device complexity increases

Engineering Contradiction:

Improvemanufacturing efficiencyVSAvoidtesting complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The VCSEL design incorporates universal features such as standardized contact configurations and uniform aperture patterns that enable the same testing and handling procedures to be applied across multiple devices on a wafer. This universality allows efficient wafer-level testing without requiring complex device-specific procedures for each VCSEL.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 device reliability, scalability, and operational flexibility by distributing optical power density, enabling efficient heat dissipation and broad wavelength operation, while facilitating precise lens placement and wafer-level testing.

Implementation Method 1

Methodology Applied

Scientific EffectLens focusing: Lens

Implementation Method 2

A VCSEL design incorporating a substrate with an aperture for light emission, featuring an opaque bottom layer for heat dissipation

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS9865983B2VCSEL incorporating a substrate having an aperture

Publication Date: 2018.01.09 AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE LTD

AI summary

A vertical cavity surface emitting laser (VCSEL) includes a substrate having an aperture that allows light generated in an active layer of the VCSEL to exit the VCSEL after propagation through a first set of semiconductor layers. The VCSEL further includes an opaque bottom layer that blocks light generated in the active layer and propagated through a second set of semiconductor layers. The opaque bottom layer can be attached to a heat sink for heat dissipation thereby allowing the VCSEL to be operated at high power levels. The active layer is sandwiched between the first set of semiconductor layers and the second set of semiconductor layers. Unlike a traditional VCSEL where only certain wavelengths of light can propagate through a solid substrate that is “transparent” to these particular wavelengths, the aperture provided in the substrate of a VCSEL in accordance with the disclosure allows for propagation of many different wavelengths.