Detuned Concentric Mirror Resonator for High Power Laser
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional enhancement resonators face limitations in generating high power and photon flux density due to mirror reflectivity losses, nonlinearities, and thermal issues, which restrict average power to below 80 kW and require complex mirror designs for oblique incidence, leading to significant losses and damage.
Innovation Solution
The use of a detuned concentric mirror configuration in the enhancement resonator, where consecutive curved mirrors form pairs with reduced distance and angle deviations, allowing for increased beam radius on mirrors and reduced focal radius, enabling higher photon flux densities and stable operation up to 1 MW with lower nonlinear mirror response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional resonator mirrors with 99.9% reflectivity are used, then the resonator can be manufactured with standard components, but the photon flux density is limited due to cumulative losses of at least 4000 ppm
Solution Approach 1:
The patent changes the optical parameters of the resonator system by introducing a telescope with specific magnification (M) and adjusting the beam radius on the mirrors. By optimizing the beam radius to a specific value (e.g., 1/e² beam radius of 1-5 mm), the system achieves optimal coupling between the laser mode and resonator mode, maximizing photon flux density while accounting for mirror losses.
2Power
If tuned dielectric resonator mirrors with 30-100 ppm reflectivity loss are used, then intra-resonator power enhancement can be increased up to 1000 times, but optical nonlinearities and thermal effects cause mirror surface destruction and scattering losses
Solution Approach 1:
The patent optimizes the beam radius parameter on the mirror surfaces to specific values (1/e² beam radius of 1-5 mm) that balance two competing requirements: large enough beam radius to reduce photon flux density and avoid nonlinear optical effects and thermal damage, but small enough to maintain high intra-resonator power enhancement. This parameter optimization allows operation at average powers up to 80 kW without mirror damage.
Solution Approach 2:
The patent replaces the conventional direct coupling approach with a telescope-based mode matching system. The telescope transforms the laser beam parameters to optimally match the resonator mode, enabling efficient energy coupling while distributing the energy over an optimized beam area that prevents mirror damage from nonlinearities and thermal effects.
3Quantity of substance
If the beam radius on mirrors is reduced to increase photon flux density, then higher power enhancement is achieved, but nonlinear mirror response and thermal aberrations increase
Solution Approach 1:
The patent establishes specific parameter ranges for the beam radius on mirrors (1/e² beam radius of 1-5 mm) that optimize the balance between photon flux density and avoidance of harmful nonlinear effects. This parameter optimization, combined with the telescope magnification factor M, enables the system to achieve high intra-resonator power enhancement while maintaining linear mirror response and minimizing thermal aberrations.
4Object-affected harmful factors
If oblique incidence mirror configuration is used, then beam radius on mirrors can be increased to reduce photon flux density, but device complexity and mirror alignment requirements increase significantly
Solution Approach 1:
The patent replaces the complex oblique incidence mirror configuration with a simpler normal incidence resonator design combined with a telescope for mode matching. The telescope performs the beam transformation function that would otherwise require complex mirror geometries, significantly simplifying the resonator structure while achieving the same goal of optimizing beam radius to reduce photon flux density on mirrors.
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 configuration achieves higher average power and photon flux densities within the resonator, reducing nonlinear effects and thermal aberrations, while maintaining stability and allowing for flexible output coupling, thus overcoming the limitations of conventional designs.
Implementation Method 1
two consecutive curved mirrors form at least two detuned concentric mirror pairs... allowing for increased beam radius on mirrors and reduced focal radius
Implementation Method 2
reducing nonlinear effects and thermal aberrations... while maintaining stability
Implementation Method 3
coherent addition of laser light in an enhancement resonator... stable operation up to 1 MW
Data Source
AI summary
A method of generating intra-resonator laser light (1) comprises the steps of coupling input laser light (2), e. g. laser pulse or continuous-wave light, into an enhancement resonator (20), which comprises at least two curved resonator mirrors (21, 22, 23, 24) and which is free of a laser light amplifying medium, said at least two curved resonator mirrors (21, 22, 23, 24) being consecutively arranged and spanning at least one resonator path with a predetermined resonator length (Lres), wherein said at least two curved resonator mirrors (21, 22, 23, 24) providing at least two pairs of consecutive curved resonator mirrors which are serially coupled along said at least one resonator path, and coherent addition of the input laser light (2) in the enhancement resonator so that the intra-resonator laser light (1) is formed, wherein said at least two pairs of consecutive curved resonator mirrors each have a detuned concentric configuration, which deviates from a concentric configuration with regard to at least one of a distance between the curved mirrors. and an angle of incidence on the curved mirror surfaces. Furthermore, an enhancement resonator (20), in particular being configured for generating intra-resonator laser light (1), a laser device (100) including the enhancement resonator device (20) and applications of the enhancement resonator device (20) are described.