Diode Laser Wavelength Locking for Scalable Narrow-Band Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional high-power diode laser systems face challenges in scaling output power and maintaining a narrow bandwidth due to difficulties in aligning and adjusting the wavelength of individual lasers, leading to scattered output beams and operational inefficiencies, especially in continuous applications.
Innovation Solution
A high-power diode laser system incorporating a plurality of diode lasers, a fiber beam combiner, and a controller with a wavelength sensor and control processor to automatically tune and lock the wavelength of each diode laser, using volume Bragg grating devices and a MEMS optical switch for precise alignment and temperature control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple diode lasers are combined using a fiber bundle, then output power is increased, but the output beam becomes scattered and difficult to focus
Solution Approach 1:
The system segments the laser combining process into two distinct stages: first combining beams in free space using polarization beam combiners to maintain a unified beam profile, then coupling the combined beam into a fiber for power aggregation. This segmentation prevents the beam profile degradation that would occur if fibers were used for the initial combining stage.
Solution Approach 2:
The invention transitions from a single-dimension fiber-based combining approach to a multi-dimensional approach that combines free-space optical combining (maintaining beam quality) with fiber coupling (enabling power scaling). This dimensional transition allows simultaneous achievement of high power and good beam profile.
2Manufacturing precision
If manual wavelength adjustment is performed for each diode laser, then wavelength alignment can be achieved, but operational efficiency decreases and frequent adjustments are required
Solution Approach 1:
The system implements a feedback mechanism using a wavelength sensor that continuously monitors the combined laser output and provides real-time wavelength deviation information. This feedback enables automatic wavelength adjustment, eliminating the need for manual intervention and maintaining optimal performance over extended operational periods.
Solution Approach 2:
The wavelength sensor and control system enable the laser system to self-adjust its wavelength alignment automatically. The system monitors its own performance and makes necessary corrections without external intervention, thereby maintaining wavelength precision while maximizing operational efficiency.
3Power
If a polarization beam splitter is used to combine two diode lasers, then output power is doubled, but the system requires careful control of polarization and beam propagation angle
Solution Approach 1:
The invention introduces fiber optic components as intermediaries between the diode lasers and the polarization beam combiner. These fiber components pre-align and condition the laser beams, reducing the sensitivity to polarization and angle control during the combining process. This intermediary approach simplifies the overall system operation while maintaining the power-doubling benefit.
4Power
If fiber bundle is used to combine diode lasers, then output power is increased, but individual wavelength adjustment becomes practically difficult
Solution Approach 1:
The system segments the combining process so that wavelength adjustment can be performed on individual laser beams before they enter the fiber bundle. By separating the wavelength adjustment stage from the fiber coupling stage, the system maintains ease of wavelength tuning while still achieving power scaling through fiber-based combination.
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 achieves scalable output power with a narrow bandwidth, maintaining alignment and stability over time, reducing the need for manual adjustments and minimizing wavelength deviations, thus enhancing operational efficiency and absorption efficiency in optical pumping applications.
Implementation Method 1
each diode laser comprises a volume Bragg grating (VBG) device. A VBG device is characterized by a Bragg wavelength and is configured to selectively amplify a light beam inside the diode laser at the Bragg wavelength
Implementation Method 2
The fiber beam combiner is configured to output a combined laser beam by combining a plurality of output laser beams generated by the plurality of diode lasers
Data Source
AI summary
The present application discloses a high-power diode laser system configured to generate scalable output power. The laser system comprises a plurality of diode lasers, a fiber beam combiner, and a controller. Each of the plurality of diode lasers is configured to generate an output laser beam. The fiber beam combiner is configured to output a combined laser beam by combining a plurality of output laser beams generated by the plurality of diode lasers. The controller is configured to tune each diode laser in the plurality of diode lasers to align a wavelength of each output laser beam in the plurality of output laser beams.