VCSEL Current-Blocking DBR for Matrix-Addressable Arrays
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Solution Overview
Problem
Existing VCSEL arrays face challenges in achieving matrix-addressability on conductive substrates, which are prone to current cross-talk and require additional isolation layers, increasing complexity and cost.
Innovation Solution
Incorporating a current-blocking DBR with alternating p-n junctions connected vertically in series, which provides both electrical isolation and optical reflection, simplifying the epitaxial structure and reducing the need for additional isolation layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional isolation layers are added to prevent current cross-talk in VCSEL arrays on conductive substrates, then electrical isolation between emitters is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the electrical isolation function and optical reflection function into a single integrated layer structure. The alternating p-n junction layers form a current-blocking DBR that simultaneously provides electrical isolation between emitters and optical reflection for laser operation, eliminating the need for separate isolation layers and reducing overall device complexity
Solution Approach 2:
The current-blocking DBR structure serves multiple functions: it acts as an electrical isolator to prevent current cross-talk between adjacent emitters, serves as an optical reflector for laser cavity formation, and provides bidirectional current blocking capability. This multi-functional design reduces the number of components needed in the VCSEL array
2Reliability
If additional isolation layers are added to prevent current cross-talk in VCSEL arrays, then electrical isolation between emitters is improved, but manufacturing cost increases
Solution Approach 1:
The patent combines the electrical isolation function and optical reflection function into a single integrated layer structure. The alternating p-n junction layers form a current-blocking DBR that simultaneously provides electrical isolation between emitters and optical reflection for laser operation, eliminating the need for separate isolation layers and reducing overall device complexity
Solution Approach 2:
The current-blocking DBR structure serves multiple functions: it acts as an electrical isolator to prevent current cross-talk between adjacent emitters, serves as an optical reflector for laser cavity formation, and provides bidirectional current blocking capability. This multi-functional design reduces the number of components needed in the VCSEL array
3Device complexity
If device thickness is reduced to simplify VCSEL structure, then manufacturing complexity is reduced, but optical power density may be compromised
Solution Approach 1:
The patent combines the electrical isolation function and optical reflection function into a single integrated layer structure. The alternating p-n junction layers form a current-blocking DBR that simultaneously provides electrical isolation between emitters and optical reflection for laser operation, eliminating the need for separate isolation layers and reducing overall device complexity
Solution Approach 2:
The patent uses alternating p-type and n-type semiconductor layers with different refractive indices to create a composite DBR structure. This composite material approach enables both electrical isolation through p-n junctions and optical reflection through refractive index contrast, achieving multiple functions within a compact thickness
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 current-blocking DBR effectively isolates emitters in a VCSEL array, enabling matrix-addressability without increasing device thickness, thus reducing complexity and cost while maintaining high optical power density.
Implementation Method 1
a current-blocking DBR arranged on the substrate, wherein the current-blocking DBR includes a plurality of p-n junctions connected vertically in series to form a bidirectional current-blocking structure
Implementation Method 2
two distributed Bragg reflector (DBR) mirrors arranged parallel to a wafer surface with an active region arranged between the two DBR mirrors
Data Source
AI summary
An emitter includes a substrate; a current-blocking distributed Bragg reflector (DBR) arranged on the substrate, wherein the current-blocking DBR includes a plurality of p-n junctions connected vertically in series to form a bidirectional current-blocking structure; a bottom contact layer arranged on the current-blocking DBR; a bottom DBR arranged on the bottom contact layer; a top DBR arranged on the bottom DBR; an active region configured to generate a laser light, wherein the active region is arranged between the bottom DBR and the top DBR; a top contact layer arranged on the top DBR; and an optical output arranged over the top DBR, wherein the emitter is configured to emit the laser light via the optical output.