Nonlinear Crystal Multi-Wavelength Generation via Merging
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Solution Overview
Problem
Existing laser systems for generating multiple wavelengths through second harmonic generation (SHG) face challenges in scalability, complexity, and the difficulty of combining multiple SH output beams into a single output, leading to issues with size, weight, power, cost, and reliability, as well as requiring high precision in spatial and spectral alignment.
Innovation Solution
A system and method that utilize a single nonlinear crystal with multiple quasi-phase-matching gratings and fiber-based components, including a waveform generator, splitters, wavelength shifters, and combiners, to generate multiple co-propagating wavelengths by splitting and shifting a pulsed laser beam, allowing for efficient nonlinear wavelength conversion and alignment of multiple SH wavelengths into a single output beam.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple separate SHG processes are used to generate multiple wavelengths, then multiple wavelengths can be generated, but the system complexity and size increase
Solution Approach 1:
The patent combines multiple second harmonic generation processes into a single nonlinear crystal by integrating multiple pump beams at different wavelengths simultaneously. This merging approach allows generation of multiple SH wavelengths (e.g., 532nm, 480nm, 450nm) from a single crystal rather than requiring separate SHG modules for each wavelength, thereby reducing system complexity while maintaining multi-wavelength capability
Solution Approach 2:
The nonlinear crystal is designed to perform multiple functions simultaneously by supporting multiple phase-matched SHG processes within the same device. The crystal structure and orientation are configured to enable concurrent generation of multiple harmonic wavelengths from different pump beams, making a single component serve multiple wavelength generation purposes
2Adaptability or versatility
If multiple SH output beams are combined into a single output, then a unified beam is achieved, but alignment precision requirements increase
Solution Approach 1:
The patent performs preliminary wavelength selection and beam configuration before the SHG process by using a programmable laser source to generate multiple pump wavelengths in advance. The beam splitter and combiner are pre-configured to direct specific wavelength components to appropriate regions of the nonlinear crystal, establishing the correct spatial and spectral alignment conditions before the actual harmonic generation occurs
Solution Approach 2:
The patent introduces a beam combiner as an intermediary device that merges multiple SH output beams into a single unified beam. This intermediary component facilitates the combination process by providing a structured method for integrating multiple beams with different wavelengths while maintaining their co-propagation, thereby managing the alignment requirements through a dedicated optical element
3Volume of moving object
If a single nonlinear crystal is used for multiple wavelength conversion, then system size is reduced, but the difficulty of achieving phase matching for multiple wavelengths increases
Solution Approach 1:
The patent segments the nonlinear crystal into multiple functional regions, each optimized for specific wavelength conversion processes. By dividing the crystal into distinct zones with different orientations or properties, each region can be independently phase-matched for specific pump-SH wavelength combinations, allowing multiple wavelength conversions to occur simultaneously within the same crystal while maintaining phase matching conditions
Solution Approach 2:
The patent utilizes temperature tuning as a parameter change mechanism to achieve and maintain phase matching for multiple wavelengths. By controlling the crystal temperature, the refractive indices and phase velocities can be adjusted to satisfy phase matching conditions for different wavelength combinations, enabling flexible multi-wavelength operation from a single crystal
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 approach reduces the complexity and size of the system, enables efficient generation of multiple co-propagating wavelengths with improved reliability and reduced alignment requirements, and achieves high SHG conversion efficiency while minimizing the need for precise tuning and free-space optics.
Implementation Method 1
at least one nonlinear crystal configured to receive the multi-wavelength beam and generate multiple co-propagating beams using nonlinear wavelength conversion
Data Source
AI summary
A system includes a waveform generator configured to generate a pulsed laser beam at a first wavelength. The system also includes at least one splitter configured to split the laser beam into multiple beams at the first wavelength. The system also includes at least one wavelength shifter configured to shift at least one of the multiple beams to another wavelength. The system also includes at least one combiner configured to combine the multiple beams into a multi-wavelength beam in which multiple wavelengths are co-aligned and propagating parallel to each other. The system also includes at least one nonlinear crystal configured to receive the multi-wavelength beam and generate multiple co-propagating beams using nonlinear wavelength conversion.