Mechanically Isolated OPS Laser Cantilever Platform

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Solution Overview

Problem

Existing OPS-laser packaging is prone to misalignment due to thermal or mechanical stress, leading to mode-hopping and output noise, as the housing distortion affects the alignment of the pump-radiation spot and the oscillating mode of the laser-resonator.

Innovation Solution

A mechanically isolated OPS-laser design featuring a cantilever platform with a heat-sink attached to one end, supported on a baseplate with a gap between the cantilever's extended portion and the baseplate, which maintains the pump-radiation spot alignment by effectively fixing the OPS-chip and resonator, reducing the impact of thermal and mechanical stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If OPS-laser resonator and pump-radiation source are packaged together in a single housing, then device integration is improved, but misalignment occurs under thermal or mechanical stress

Engineering Contradiction:
Improvedevice integrationVSAvoidalignment precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent divides the housing into two separate sections: a first housing for the OPS-laser resonator and a second housing for the pump-radiation source. This segmentation allows each component to be independently mounted and aligned, preventing stress-induced misalignment while maintaining integration. The resonator is mounted on a first substrate in the first housing, while the pump source is mounted on a second substrate in the second housing, with optical coupling between them.

Inventive Principle:
Principle #1Segmentation

2Strength

If housing is made rigid for structural stability, then mechanical strength is improved, but thermal stress distortion increases

Engineering Contradiction:
Improvestructural stabilityVSAvoidthermal stress distortion
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent introduces optical elements (lenses, mirrors, or fiber optic couplers) as intermediaries between the pump-radiation source and the OPS-laser resonator. These intermediaries are mounted on separate substrates that can accommodate thermal expansion and stress independently, while still maintaining precise optical coupling. This allows the housing to be rigid for structural stability while preventing stress transmission that would cause misalignment.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If components are mounted directly on baseplate for simplicity, then device complexity is reduced, but alignment stability deteriorates

Engineering Contradiction:
Improvemounting structure simplicityVSAvoidalignment stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent employs adjustable mounting mechanisms that allow for dynamic alignment adjustment. The pump-radiation source and resonator can be independently positioned and adjusted on their respective substrates to achieve optimal alignment. This dynamic adjustment capability ensures stable alignment under varying thermal and mechanical conditions while maintaining reasonable device complexity through standardized mounting interfaces.

Inventive Principle:
Principle #15Dynamics

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 design minimizes misalignment and output noise by maintaining the oscillating mode's position on the gain-structure, ensuring stable operation under thermal or mechanical stress conditions.

Implementation Method 1

an OPS-chip bonded to a heat-sink attached to the first end of the cantilever platform

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

A pump-radiation supply is mounted on the first surface of the baseplate and arranged to deliver optical pump radiation to the OPS-chip for energizing the OPS laser-resonator

Methodology Applied
Scientific EffectLight emission: Light

Data Source

PatentEP3488507B1Mechanically isolated optically pumped semiconductor laser
Publication Date: 2021.12.08 COHERENT INC
  • EP3488507B1 patent drawingFigure 1A~1B

AI summary

A housing for an optically pumped semiconductor (OPS) laser resonator is terminated at one end thereof by an OPS-chip. The laser resonator is assembled on a platform with the OPS-chip at one end of the platform. The platform is fixedly attached to a baseplate at the OPS-chip end of the platform. The remainder of the platform extends over the baseplate with a gap between the platform and the baseplate. A pump-laser is mounted directly on the baseplate and delivers pump radiation to the OPS-chip.