Transverse Drive Kinematic Optic Mount for Beam Stability

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Solution Overview

Problem

Current vertical drive kinematic optic mounts suffer from poor beam pointing stability due to thermal expansion, crosstalk between pitch and yaw adjustments, and mechanical stress, which results in suboptimal adjustment performance and beam steering issues.

Innovation Solution

A transverse drive kinematic optic mount that converts rotational radial motion into axial lineal motion at an angle, allowing for adjustable orientation of the adjuster screw and using hardened kinematic contacts and precision machined components to minimize crosstalk and thermal expansion effects, with a tightly constrained kinematic structure to maintain stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a vertical drive mount with fixed wedge pusher is used, then the structure is simple, but beam pointing stability deteriorates due to thermal expansion and crosstalk

Engineering Contradiction:
Improvestructure simplicityVSAvoidbeam pointing stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent inverts the conventional vertical drive orientation to a transverse drive orientation. The adjuster screw is positioned transverse to the pusher piston axis rather than vertically aligned, which fundamentally changes the thermal expansion behavior and eliminates the crosstalk between pitch and yaw adjustments that plagues vertical designs.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The invention moves the drive mechanism from a vertical dimension to a transverse dimension. This dimensional shift allows the adjuster screw to be positioned away from the beam path while maintaining effective optical adjustment, and creates a geometry where thermal expansion occurs perpendicular to the adjustment axis, eliminating beam steering issues.

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

2Volume of moving object

If the adjuster screw is positioned close to the beam path for compact design, then the device size is reduced, but beam obstruction and image quality deteriorate

Engineering Contradiction:
Improvedevice sizeVSAvoidbeam obstruction
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The transverse positioning of the adjuster screw moves it to a different spatial dimension relative to the beam path. Instead of being vertically aligned with or close to the beam, the screw extends horizontally from the mount body, allowing compact vertical profile while completely avoiding beam obstruction.

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

3Volume of moving object

If flexure type vertical drives with compact packaging are used, then the device size is reduced, but material stress increases causing poor beam pointing stability

Engineering Contradiction:
Improvedevice sizeVSAvoidmaterial stress
Core Design Contradiction:
Volume of moving objectVSStrength

Solution Approach 1:

Instead of using flexure elements that rely on elastic deformation, the patent inverts to a rigid transverse drive mechanism with a screw-threaded adjuster and pusher piston. This eliminates the high material stresses inherent in flexure designs and their associated drift problems from stress relaxation and temperature cycling.

Inventive Principle:
Principle #13The other way round (Inversion)

4Device complexity

If the adjuster screw is oriented longitudinally for simple conversion, then the mechanism is simple, but adjustment resolution and range are limited

Engineering Contradiction:
Improvemechanism simplicityVSAvoidadjustment resolution
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent changes the geometric parameters of the drive mechanism by orienting the screw axis transverse to the pusher piston rather than longitudinally. This parameter change allows the use of a wedge ratio in the transverse orientation, enabling the system to achieve either high resolution with reduced travel or extended adjustment range with acceptable resolution, depending on the specific wedge angle chosen.

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 transverse drive kinematic optic mount achieves improved beam pointing stability over temperature and vibration, reduced crosstalk, and enhanced adjustment resolution with controlled kinematic movement, outperforming traditional mounts in terms of stability and precision.

Implementation Method 1

a drive adjuster (130) configured to move along a first direction and the drive adjuster is in contact with a ramp on a pusher piston (140), such that a movement of the drive adjuster causes the pusher piston (140) to move along a second direction

Methodology Applied
Scientific EffectMechanical motion conversion: Mechanical Advantage

Data Source

PatentEP3859966B1Transverse drive kinematic optic mount
Publication Date: 2023.03.08 THORLABS INC
  • EP3859966B1 patent drawingFigure 1
  • EP3859966B1 patent drawingFigure 2
  • EP3859966B1 patent drawingFigure 3

AI summary

An optical mount including a first frame and a second frame; wherein the first frame includes a drive adjuster configured to move along a first direction and the drive adjuster is in contact with a ramp on a pusher piston, such that a movement of the drive adjuster causes the pusher piston to move along a second direction; wherein the pusher piston is configured to push kinematic contacts on the second frame resulting in a controlled movement of the second frame by the drive adjuster.