Spherical Array Laser Source for High Efficiency Fiber Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Arrays of semiconductor laser sources face inefficiencies in coupling into single mode waveguides due to lossy coupling methods, which reduce the efficiency of laser sources and optical amplifiers.
Innovation Solution
A spherical mounting configuration for an array of laser sources, where the emission axes are aligned with the radius of a reflecting spherical substrate, combined with a single mode waveguide and a reflector, forms a cavity that enhances optical coupling efficiency by matching modes between the emitters and the fiber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If planar arrays of emitters are used with conventional coupling methods, then the structure is simple to manufacture, but the coupling efficiency into single mode fiber is low
Solution Approach 1:
The patent employs a spherical array configuration where multiple laser emitters are arranged on the surface of a sphere with their emission axes pointing toward the center of curvature. This spherical geometry naturally focuses the emitted beams to a common focal point, enabling efficient coupling into single mode fiber without complex optical assemblies. The curvature of the spherical arrangement transforms the divergence of individual emitters into a concentrated beam pattern that matches the fiber's mode field distribution.
2Loss of energy
If complex optical assemblies are used to focus planar array output, then coupling efficiency improves, but the device complexity increases
Solution Approach 1:
The patent merges the functions of multiple emitters into a unified spherical array structure where all emitters share a common focal point and optical path. By combining the emission sources and their focusing function into a single integrated spherical configuration, the system achieves efficient fiber coupling without requiring separate optical assemblies for each emitter or complex beam combining mechanisms.
Solution Approach 2:
The spherical arrangement of emitters with axes pointing to the center of curvature creates an inherent focusing effect that eliminates the need for additional focusing optics. This geometric configuration naturally converges the beams to a single focal point, simplifying the overall device structure while maintaining high coupling efficiency.
3Ease of operation
If splicing of single mode fibers from individual emitters is used, then each emitter can be coupled, but the overall system efficiency is reduced
Solution Approach 1:
The patent combines the output of multiple emitters into a single focused beam that couples into one single mode fiber. This merging approach eliminates the need for multiple fiber splices and associated losses, achieving higher overall system efficiency by consolidating the optical paths while maintaining ease of operation through a unified coupling interface.
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
This configuration achieves high optical output power with improved coupling efficiency, exceeding 90% into a single mode fiber, overcoming the limitations of existing methods by aligning the emitters' emission axes with the spherical substrate's radius and using a lenslet array for precise alignment and mode matching.
Implementation Method 1
A reflector substantially coincident with an end of the waveguide combines with the reflecting spherical substrate to form a cavity
Implementation Method 2
A lenslet array may be provided in certain embodiments between the emitters and fiber end
Implementation Method 3
Each emitter has an emission axis of symmetry aligned with a radius of the spherical substrate
Data Source
AI summary
A laser cavity is provided by a reflecting spherical substrate with an array of emitters having a mode size. Each emitter has an axis aligned with a radius of the spherical substrate. A single mode waveguide is aligned with the array at an optical coupling distance less than the radius of the spherical substrate. A reflector substantially coincident with an end of the waveguide combines with the reflecting spherical substrate as a cavity.