Beam-Shaped Pump Optics for Higher-Radiance Laser Sustained Plasma
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing bell-shaped, Gaussian/near-Gaussian distribution of pump lasers in laser sustained plasma (LSP) sources does not provide optimal pump laser distribution for plasma performance, particularly limiting plasma radiance at higher operation powers.
Innovation Solution
The system reshapes the pump beam to achieve a modified pupil power distribution, such as flat-top or inverted distributions with a central local intensity minimum, using beam shapers and focusing optics to improve plasma radiance by redistributing radiant power within the available pump solid angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If bell-shaped, Gaussian/near-Gaussian pump laser distribution is used, then the system structure remains simple, but plasma radiance is limited at higher operation powers
Solution Approach 1:
The patent changes the parameter of pump laser power distribution from Gaussian to modified distributions (flat-top, inverted, or truncated) to improve plasma radiance. This is achieved by introducing beam shaping optics that redistribute the laser power spatially, transforming the intensity profile to concentrate more energy in specific angular ranges that enhance plasma emission efficiency.
Solution Approach 2:
The patent applies local quality by creating non-uniform pump laser distribution with specific intensity minima and maxima at different angular positions. The modified pupil power distribution places higher intensity in certain angular regions and lower intensity in others, optimizing energy deposition in different plasma zones to maximize radiance while controlling plasma growth direction.
2Temperature
If pump laser power is increased to improve plasma radiance, then plasma brightness increases, but plasma grows toward the pump source reducing delivery efficiency
Solution Approach 1:
The patent modifies the angular distribution parameter of pump laser power to prevent plasma growth toward the source. By creating intensity minima at low angles and concentrating power at higher angles, the plasma is sustained away from the pump source, maintaining a clear optical path and improving laser power delivery efficiency to the plasma focus region.
Solution Approach 2:
The patent inverts the conventional Gaussian distribution by creating an inverted distribution where the center has a local intensity minimum and the maxima are at non-zero angles. This inversion prevents plasma from growing toward the pump source by reducing intensity in the direction of plasma propagation, thereby improving energy delivery efficiency.
3Temperature
If simple focusing optics are used, then the system is easy to manufacture, but the pupil power distribution is not optimal for plasma performance
Solution Approach 1:
The patent introduces beam shaping optics as an intermediary component between the pump laser and the plasma. These optics (such as aspheric lenses or diffractive optical elements) serve as a mediator to transform the Gaussian beam profile into the desired modified distribution, achieving optimal plasma performance without requiring complex custom-designed focusing optics.
Solution Approach 2:
The patent changes the power distribution parameter of the pump laser by introducing beam shaping elements. These elements modify the spatial intensity profile from Gaussian to flat-top, inverted, or truncated distributions, optimizing the angular power distribution to enhance plasma radiance while using commercially available optical components.
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 results in a smaller, hotter, and brighter plasma with improved delivery efficiency of laser power to the focus, enhancing plasma radiance and sustainability conditions closer to the pump source focus.
Implementation Method 1
one or more beam shapers to reshape the pump beam to provide a shaped pupil power distribution at an illumination pupil plane of the one or more focusing optics
Implementation Method 2
the one or more focusing optics receive the pump beam from the one or more beam shapers and direct the pump beam to a plasma-forming material
Implementation Method 3
the pump beam at least one of forms or maintains a plasma that emits broadband illumination
Implementation Method 4
a plasma that emits broadband illumination
Data Source
AI summary
A system for generating pump illumination for laser sustained plasma (LSP) is disclosed. The system may include an illumination source configured to output a pump beam, one or more focusing optics, and one or more beam shapers configured to reshape the pump beam to provide a shaped pupil power distribution at an illumination pupil plane of the one or more focusing optics. The shaped pupil power distribution may include at least one of a flat-top distribution or an inverted distribution with a central local intensity minimum. Further, the one or more focusing optics may receive the pump beam from the one or more beam shapers and direct the pump beam to a plasma-forming material, whereby the pump beam at least one of forms or maintains a plasma that emits broadband illumination.