Immersion Grating Prism for High-Power Beam Combining

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current laser beam combination systems face limitations in output power due to thermal, nonlinear, and material effects, and existing spectral beam combination methods require mechanical stabilization and are susceptible to environmental contamination, leading to increased cost, size, and complexity.

Innovation Solution

A monolithic beam combination system using an immersion grating prism that eliminates the need for mechanical stabilization and protects the grating surface from contaminants by using a protective cap, allowing for high-power, spatially coherent output over a narrow spectral band without mechanical stabilization or environmental sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical stabilization is used in spectral beam combination systems, then beam combination stability is improved, but system complexity and cost increase

Engineering Contradiction:

Improvebeam combination stabilityVSAvoidsystem complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical stabilization systems with an all-optical solution using an immersion grating prism. The grating is immersed in a high-index refractive index medium (such as sapphire or glass) which provides both the diffraction function and mechanical stability, eliminating the need for separate mechanical stabilization components while maintaining beam combination stability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent merges the diffraction grating function with the prism structure by immersing the grating in a high-index medium. This integration combines multiple functions (diffraction, beam combination, and mechanical support) into a single monolithic component, reducing system complexity while maintaining reliability.

Inventive Principle:

Principle #5Merging (Combining)

2Device complexity

If the grating surface is exposed to environment, then system simplicity is maintained, but contamination and damage occur

Engineering Contradiction:

Improvesystem simplicityVSAvoidcontamination

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent creates a protected environment for the grating surface by immersing it in a high-index refractive index medium such as sapphire or glass. This immersion creates a physical barrier that protects the grating from environmental contaminants while maintaining optical functionality, effectively creating an inert protective environment around the sensitive grating surface.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

Solution Approach 2:

The high-index immersion medium acts as an intermediary between the grating surface and the external environment. It provides both optical functionality (enabling diffraction) and physical protection (preventing contamination), serving as a mediator that simultaneously addresses optical performance and environmental protection requirements.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Power

If multiple laser beams are added together to increase output power, then power is improved, but beam quality deteriorates due to spatial incoherence

Engineering Contradiction:

Improveoutput powerVSAvoidbeam quality

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The patent changes the spectral parameter of the laser beams by diffracting them through an immersion grating. This spectral separation and subsequent recombination allows multiple beams to be combined while maintaining spatial coherence, as the grating introduces controlled phase relationships between the beams based on their wavelengths, thereby preserving beam quality while increasing output power.

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 solution provides improved beam quality and reliability by eliminating the need for mechanical stabilization and protecting the grating from environmental damage, reducing system complexity and cost while maintaining high-power output.

Implementation Method 1

an immersion grating operable to diffract light propagating from the collimator

Methodology Applied

Scientific EffectDiffraction: Diffraction

Implementation Method 2

The collimator is operable to reflect and collimate light propagating from the fiber entry block

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 3

The output surface of the prism body is operable to pass light propagating from the immersion grating

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS11726341B2Method and system for multispectral beam combiner

Publication Date: 2023.08.15 RAM PHOTONICS INDUSTRIAL LLC

AI summary

A spectral beam combining system includes a plurality of input fibers and a prism having a curved input surface. The plurality of input fibers are attached to the curved input surface. The spectral beam combining system also includes an immersion grating defined on a second surface of the prism, a protective cap disposed over the immersion grating, and an output surface.