DBR Mirror Beam Extraction Using a Porous Piezoelectric Layer

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Solution Overview

Problem

Current laser systems for fusion energy generation face limitations in handling high-power laser beams due to physical constraints and damage thresholds of optical components, necessitating improvements to efficiently extract and control laser beams beyond the intensity limits of solid-state optics.

Innovation Solution

A hybrid distributed Bragg reflector (DBR) mirror system using piezoelectric materials with intentionally introduced pores or voids to achieve a significant refractive index contrast, allowing for the extraction of high-power laser beams through DBR mirrors by applying surface acoustic waves or electric fields, thereby overcoming the limitations of conventional acousto-optic modulators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If conventional acousto-optic modulators are used to extract laser beams, then the system can control laser beams, but the damage threshold and intensity limits of solid-state optics restrict the maximum power handling capability

Engineering Contradiction:
Improvelaser beam powerVSAvoiddamage threshold of optical components
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent applies porous materials by introducing a porous layer within the DBR mirror structure. This porous layer enables dynamic control of laser beam extraction through acoustic wave modulation while the distributed Bragg reflector design distributes the optical stress across multiple thin layers, preventing localized damage and enabling handling of higher power laser beams beyond conventional solid-state optic limits.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent uses composite materials by combining the DBR mirror structure (multiple alternating layers of high and low refractive index materials) with a porous active layer that contains the piezoelectric material. This composite structure integrates the high reflectivity of DBR mirrors with the dynamic modulating capability of the porous piezoelectric layer, achieving both high power handling and controllable beam extraction.

Inventive Principle:
Principle #40Composite materials

2Power

If the mirror area is increased to reduce energy density and handle higher power, then the system can process higher power laser beams, but the device complexity and cost increase

Engineering Contradiction:
Improvelaser beam powerVSAvoidmirror area and system complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the mirror into a DBR structure consisting of multiple thin alternating layers of high and low refractive index materials. This segmentation allows the mirror to achieve high reflectivity while distributing the energy density across many thin layers, preventing localized damage and enabling high power handling without requiring excessively large mirror areas.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from conventional single-layer or few-layer mirror designs to a multi-layer DBR structure, adding dimensional complexity in the vertical stacking direction. This vertical dimensionality allows the system to achieve the required optical performance with smaller footprint areas by stacking functionality rather than expanding laterally.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of operation

If a piezoelectric layer with voids is used to change refractive index by more than 0.0001, then the laser beam can be extracted through the DBR mirror, but the manufacturing precision and fabrication complexity increase

Engineering Contradiction:
Improvelaser beam extraction capabilityVSAvoidrefractive index control precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by utilizing the piezoelectric effect to dynamically change the refractive index of the porous layer through applied electric fields or acoustic waves. This allows the DBR mirror to transition from a high-reflectivity state to a transmission state by modifying the optical parameters of the porous layer, enabling controlled laser beam extraction without physical contact or mechanical adjustment.

Inventive Principle:
Principle #35Parameter changes

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 enables the efficient extraction and control of high-power laser beams, facilitating compact and cost-effective fusion energy generation by increasing mirror area and reducing energy density, thus enhancing the capabilities of laser systems for applications like nuclear fusion and other high-power applications.

Implementation Method 1

a piezoelectric layer configured with a plurality of stacked layers such that the piezoelectric layer is configured to the DBR. An electrical contact is coupled to the piezoelectric layer containing the voids. An electric field is supplied in the piezoelectric layer containing the voids to alter a refractive index of the piezoelectric layer

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

allowing for the extraction of high-power laser beams through DBR mirrors by applying surface acoustic waves or electric fields

Methodology Applied
Scientific EffectAcousto-optic effect: Acousto-optic Effect

Implementation Method 3

a plurality of stacked layers of materials with at least two different refractive indices to form a distributed Bragg reflector (DBR)

Methodology Applied
Scientific EffectBragg diffraction: Bragg Diffraction

Data Source

PatentEP4692919A1Laser beam extraction using distributed bragg reflector (DBR) mirror systems with a piezoelectric layer
Publication Date: 2026.02.11 BLUE LASER FUSION INC
  • EP4692919A1 patent drawingFigure 1
  • EP4692919A1 patent drawingFigure 2(a)~2(d)
  • EP4692919A1 patent drawingFigure 3(a)~3(d)

AI summary

In an example, the present invention provides a laser system. The laser system has a source laser (e.g., CBC) coupled to first mirror device opposing a second mirror device and configured to generate a resonating laser beam between the first mirror and the second mirror. In an example, the system has a piezoelectric device configured to the second mirror device and characterized by a refractive e index such that one or more voids is changed by applying an energy to the piezo electric device to cause a change in a value of the refractive index, e.g., by more than 0.0001, to allow the resonating laser beam or a portion of the resonating laser to traverse through a portion of the second mirror device.