Direct Diode Laser Wavelength Combining for High Beam Quality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light source devices using wavelength beam combining face limitations in increasing the number of laser modules due to decreased diffraction efficiency and beam quality degradation, restricting the enhancement of optical output power.
Innovation Solution
A light source device comprising a first and second light source, each combining laser beams within specific wavelength ranges, and a wavelength filter to coaxially combine these beams, allowing for increased optical output while maintaining beam quality by adjusting optical path lengths and using a dichroic mirror for wavelength selection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the number of laser modules is increased to enhance optical output power, then the optical output power is improved, but the beam quality degrades and diffraction efficiency decreases
Solution Approach 1:
The patent divides the wavelength range into multiple distinct ranges (first wavelength range and second wavelength range) and assigns different laser modules to each range. This segmentation allows each module to operate within its optimal wavelength band, maintaining beam quality while collectively achieving high optical output power through the combination of multiple segmented wavelength groups.
Solution Approach 2:
The patent introduces wavelength as an additional dimension for organizing and combining laser beams. By using a wavelength filter that selectively transmits and combines beams from different wavelength ranges, the system adds spectral dimensionality to the beam combining process, enabling scaling to twenty or more modules without the beam quality degradation that would occur in simple spatial or power scaling.
2Power
If the number of laser modules is increased to enhance optical output power, then the optical output power is improved, but the diffraction efficiency decreases
Solution Approach 1:
The patent applies local quality by optimizing each wavelength range and its corresponding laser modules independently. Each wavelength range is tailored to specific diffraction characteristics, allowing the system to maintain high diffraction efficiency within each local wavelength band while combining multiple such bands to achieve overall high optical output power.
Solution Approach 2:
The patent utilizes parameter changes by varying the wavelength parameter across different laser modules and groups. By selecting laser modules with peak wavelengths in different ranges and using a wavelength filter to combine them, the system transforms the single-parameter scaling problem into a multi-parameter optimization, maintaining diffraction efficiency through wavelength diversity while achieving high total optical output power.
3Power
If wavelength beam combining is used to increase optical output power, then the optical output power is improved, but chromatic aberration and incident angle enlargement occur
Solution Approach 1:
The patent introduces a wavelength filter as an intermediary device between the laser modules and the final beam combination point. This intermediary selectively transmits beams within specific wavelength ranges while blocking others, mediating the combination process to prevent chromatic aberration and incident angle enlargement by ensuring only compatible wavelength groups are combined.
Solution Approach 2:
The patent segments the wavelength spectrum into distinct ranges and processes each segment separately through dedicated laser modules and filter passages. This segmentation prevents the mixing of widely different wavelengths that would cause chromatic aberration, while still enabling high optical output power through the combination of multiple segmented wavelength groups.
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
Enables the combination of up to twenty or more laser modules without degrading beam quality, enhancing optical output power and fluence, and improving beam quality by suppressing the enlargement of incident angles and chromatic aberration.
Implementation Method 1
The wavelength filter is configured to coaxially combine the first wavelength-combined beam and the second wavelength-combined beam to generate and emit a third wavelength-combined beam
Implementation Method 2
using a dichroic mirror for wavelength selection
Data Source
AI summary
A light source device including: a first light source configured to coaxially combine a plurality of first laser beams, each having a peak wavelength within a first wavelength range, to thereby generate and emit a first wavelength-combined beam; a second light source configured to coaxially combine a plurality of second laser beams, each having a peak wavelength within a second wavelength range that defines a range of peak wavelengths shorter than the peak wavelengths in the first wavelength range, to thereby generate and emit a second wavelength-combined beam; and a wavelength filter configured to coaxially combine the first wavelength-combined beam and the second wavelength-combined beam to thereby generate and emit a third wavelength-combined beam.