VCSEL Filter Layout for Independent Mode and Polarization Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional laser designs face a tradeoff between side-mode suppression and polarization-mode suppression, requiring a compromise in filter diameter to achieve high suppression ratios, which limits their performance in high-speed data communication applications.
Innovation Solution
A vertical-cavity surface-emitting laser (VCSEL) design with separate mode and polarization filters, allowing independent optimization of side-mode and polarization-mode suppression ratios, featuring a mode filter on one side of the active region and a polarization filter on the other, with non-circular shapes and orientations to enhance suppression capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single filter is used for both side-mode suppression and polarization-mode suppression, then the filter diameter must be compromised, but this limits the suppression ratios for both modes
Solution Approach 1:
The patent divides the filtering function into two separate filters: a mode filter for side-mode suppression and a polarization filter for polarization-mode suppression. This segmentation allows each filter to be independently optimized for its specific function, achieving high suppression ratios for both modes without compromise.
Solution Approach 2:
The patent extracts the polarization filtering function from the mode filter, creating a dedicated polarization filter. This extraction enables independent optimization of each filter's parameters, resolving the tradeoff that previously limited both suppression ratios.
2Manufacturing precision
If separate mode and polarization filters are used, then both suppression ratios can be independently optimized, but device complexity increases
Solution Approach 1:
The mode filter and polarization filter are integrated into a unified VCSEL structure with shared components such as the active region, mirrors, and substrate. This merging approach achieves independent optimization of both suppression ratios while minimizing overall device complexity through shared infrastructure.
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 VCSEL achieves side-mode suppression ratios of 15 dB or greater and polarization-mode suppression ratios of 15 dB or greater, optimizing both suppression ratios independently without compromising performance.
Implementation Method 1
the mode filter is configured to increase a side-mode suppression ratio of the laser
Implementation Method 2
the polarization filter is configured to increase a polarization-mode suppression ratio of the laser
Implementation Method 3
the aperture may be configured for confining the electrical current and the optical field of the light via lateral oxidation
Data Source
AI summary
Some embodiments of the present disclosure are directed to a laser design that provides side-mode suppression that is separately configurable from polarization-mode suppression, such that each may be independently optimized to simultaneously provide a high side-mode suppression ratio and a high polarization-mode suppression ratio. For example, a laser (e.g., a VCSEL) may include an active region configured to emit light, an aperture defining an optical axis, a first element positioned along the optical axis on a first side of the active region, and a second element positioned along the optical axis on a second side of the active region opposite the first side of the active region. The first element may be configured to increase a side-mode suppression ratio of the laser, and the second element may be configured to increase a polarization-mode suppression ratio of the laser.