Multi-core laser rod with fold optics for pump absorption

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Solution Overview

Problem

Conventional diode bar pumped laser systems suffer from inefficiency due to limited pump light absorption within a small diameter region, leading to wasted heat, instability from separate output coupler and mirror alignment, and critical manual alignment processes that result in misalignment.

Innovation Solution

The use of multiple core clad laser rod assemblies with a cladding material providing mechanical support and acting as a reflecting cavity, where the output coupler and highly reflecting mirror are aligned on the same polished surface, and fold optics are adhesivelessly bonded to eliminate alignment issues, allowing efficient pumping with a single pump diode bar.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single pump diode bar is used to pump a small diameter laser rod, then device complexity is reduced, but pump light absorption efficiency deteriorates leading to wasted heat

Engineering Contradiction:

Improvenumber of pump diode barsVSAvoidpump light absorption efficiency

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The laser rod is divided into multiple cores (first core and second core) within a single rod structure. Each core can be independently pumped, allowing a single pump diode bar to effectively pump multiple cores, thereby improving pump light absorption efficiency without increasing the number of pump diode bars.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple laser cores are nested within a single laser rod structure with a common cladding layer. This nested configuration allows efficient coupling of pump light from a single diode bar to multiple cores through the shared cladding, improving energy absorption while maintaining simple device architecture.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Ease of manufacture

If separate mounts are used for output coupler and mirror, then ease of manufacture is improved, but stability deteriorates due to alignment instability

Engineering Contradiction:

Improveseparate component mountingVSAvoidalignment stability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The output coupler and highly reflecting mirror are merged into a single mount structure. This integration ensures stable relative alignment between the two optical components while maintaining ease of manufacture through standardized mounting interfaces. The combined mount eliminates alignment drift between separate components.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of operation

If manual alignment process is used for output coupler and mirror, then ease of operation is improved, but manufacturing precision deteriorates resulting in misalignment

Engineering Contradiction:

Improvemanual alignment adjustabilityVSAvoidalignment accuracy

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The output coupler and highly reflecting mirror are pre-aligned within the integrated mount structure during manufacturing. This preliminary alignment action ensures high manufacturing precision is achieved while maintaining ease of operation through minimal adjustment requirements during system assembly and operation.

Inventive Principle:

Principle #10Preliminary action

4Adaptability or versatility

If multiple components are used in laser system, then adaptability is improved, but device complexity increases

Engineering Contradiction:

Improvesystem configuration flexibilityVSAvoidcomponent count

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The cladding layer serves multiple functions simultaneously: it provides mechanical support for the laser cores, acts as a reflecting cavity for pump light, and facilitates thermal management. This multi-functionality reduces the need for separate components, decreasing device complexity while maintaining system adaptability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 reduces component count, simplifies assembly, increases stability, and enhances efficiency by ensuring proper alignment and heat management, while reducing costs and size, and maintaining beam quality across environmental conditions.

Implementation Method 1

a cladding material surrounding the first and second laser rods, the cladding material acting as a reflecting cavity

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 2

the RE elements in the laser rod (or core) of the laser or amplifier absorbs pump radiation of a predetermined wavelength provided by the laser diodes and, responsive thereto, provides or amplifies light of a different wavelength

Methodology Applied

Scientific EffectLaser pumping: Absorption (EM radiation)

Data Source

PatentUS9356420B1Solid state laser with multiple cores coupled by fold optics

Publication Date: 2016.05.31 GOOCH & HOUSEGO

AI summary

A laser rod assembly includes a first and second laser rod embedded in a cladding material. The assembly has a first end and a second end. The laser rods generate laser light at λlaser (λlaser light) when pumped by pump power at λpump. A reflecting outer surface at λpump is on or over a majority of an outer surface of the cladding material. Fold optic(s) on the second end provides optical coupling between the laser rods. An optical resonator includes a highly reflecting (HR) mirror at λlaser over an end of the first laser rod on the first end and an output coupler over an end of the second laser rod also on the first end.