Laser Diode Emitter Coupling via Beam Transform System
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Solution Overview
Problem
Coupling the output of multiple laser diode emitters into a single optical fiber while maintaining brightness and efficiency is challenging due to the spatial distribution of emitters, particularly when coupling to small diameter fibers.
Innovation Solution
A coupling system that includes fast and slow axis collimators, a beam transform system, and a beam combiner, such as a polarization beam combiner, to collimate, transform, and focus the output beams, ensuring effective coupling into an optical conduit like an optical fiber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If multiple laser diode emitters are spaced sufficiently apart to allow cooling, then cooling is simplified, but coupling efficiency into small diameter optical fibers deteriorates
Solution Approach 1:
The patent applies dimensionality change by transforming the spatial distribution of multiple emitter beams from a two-dimensional array into a one-dimensional collimated beam through the use of collimators and beam combining optics. This allows the beams to be efficiently coupled into the optical fiber while maintaining the beneficial spacing of emitters for cooling.
Solution Approach 2:
The patent merges multiple separate emitter beams into a single combined beam through the use of beam combining optics. This consolidation allows all emitter output to be coupled into a single optical fiber, improving overall coupling efficiency while maintaining the physical spacing of individual emitters for effective cooling.
2Device complexity
If multiple emitter beams are directly coupled into a small diameter optical fiber, then coupling complexity is reduced, but brightness and coupling efficiency deteriorate
Solution Approach 1:
The patent applies preliminary action by performing beam collimation and spatial transformation before the final coupling into the optical fiber. The collimators pre-process the divergent beams from each emitter, creating parallel beams that are easier to combine and couple efficiently into the small diameter fiber.
Solution Approach 2:
The patent introduces intermediary optical elements (collimators and beam combining optics) between the emitters and the optical fiber. These intermediaries transform the beam characteristics to enable efficient coupling while maintaining system brightness, acting as mediators that bridge the gap between the emitter array and the small fiber core.
3Temperature
If emitter spacing is increased for effective cooling, then thermal management is improved, but beam transformation and coupling difficulty increases
Solution Approach 1:
The patent segments the beam handling function into distinct optical stages: individual emitter collimation, beam combining, and final focusing. This segmentation allows each stage to be optimized independently, managing the complexity of beam transformation while maintaining effective emitter spacing for cooling.
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 system enhances the coupling efficiency and maintains the brightness of the output beams, facilitating their integration into small diameter optical fibers by redistributing and focusing the beam product between the fast and slow axes.
Implementation Method 1
collimating the output beams of the emitters along a fast axis
Implementation Method 2
collimating the output beams of the emitters along a slow axis
Implementation Method 3
transforming the output beams of each emitter by passing the output through a beam transform system
Implementation Method 4
the output beams are focused into an optical conduit input
Implementation Method 5
a beam combiner which may be a polarization beam combiner
Data Source
AI summary
Methods and devices for coupling the output of multiple emitters of a laser diode bar using a beam transform system with high brightness and coupling efficiency. Some embodiments may include wavelength locking with devices such as VBGs and other suitable devices and methods.