Cross-Cylinder Objective Assembly for Laser Diode Beam Control

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Solution Overview

Problem

Conventional laser diode packages lack independent control and optimization of beam brightness along the fast and slow axes, leading to increased complexity, cost, and alignment errors due to the use of additional optics for beam alignment.

Innovation Solution

A cross-cylinder objective assembly with separate fast axis and slow axis objectives, integrated within a lens cell that provides passive alignment and secure registration, allowing independent control of beam focus along both axes without additional optics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate fast axis and slow axis collimation optics are used, then independent control of beam brightness along both axes is achieved, but device complexity and cost increase

Engineering Contradiction:

Improveindependent control of beam brightnessVSAvoidcomplexity of optics system

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the fast axis objective and slow axis objective into a single integrated objective assembly, where both cylindrical lenses are mounted in fixed spatial relationships within a common housing. This integration allows independent control of beam brightness along both axes while reducing the number of separate components and simplifying the overall optical system.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The integrated objective assembly serves multiple functions simultaneously: it performs fast axis collimation, slow axis collimation, and beam combining in a single component structure. This multi-functionality eliminates the need for separate adjustment mechanisms for each axis, reducing device complexity while maintaining independent control capabilities.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If additional optics are included for beam alignment control, then beam brightness optimization is improved, but alignment difficulty and labor requirements increase

Engineering Contradiction:

Improvebeam brightness optimizationVSAvoidease of beam alignment

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The fast axis objective and slow axis objective are pre-aligned to specific positions and orientations within the integrated objective assembly during manufacturing. This preliminary alignment eliminates the need for complex field alignment procedures, allowing the system to achieve optimal beam brightness while simplifying installation and operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The integrated objective assembly is designed to self-align with the laser diode array through mechanical interfaces and registration features. The assembly automatically positions the fast axis and slow axis objectives in their correct spatial relationships without requiring external alignment tools or complex adjustment procedures, thereby improving ease of operation.

Inventive Principle:

Principle #25Self-service

3Manufacturing precision

If multiple separate optics are used for fast and slow axis focusing, then beam focusing precision is improved, but the chance of errors or defects increases

Engineering Contradiction:

Improvebeam focusing precisionVSAvoidreliability of beam alignment

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

By integrating both objectives into a single assembly with fixed spatial relationships, the patent reduces the number of independent alignment interfaces and potential failure points. The merged structure maintains precise focusing capability while improving reliability by eliminating errors that could arise from misalignment between separate components.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

Instead of aligning multiple separate optics to each other, the patent inverts the approach by pre-aligning both objectives to a common reference frame within the integrated assembly. This reversal of the alignment sequence reduces cumulative alignment errors and improves the overall reliability of the beam focusing system.

Inventive Principle:

Principle #13The other way round (Inversion)

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 solution simplifies beam alignment, reduces complexity and cost, and enhances beam focusing efficiency by allowing independent optimization of beam brightness along both axes, improving the overall performance of laser diode packages.

Implementation Method 1

a fast axis objective (FAO) situated along an optical axis for focusing an incident laser beam along a fast axis, a slow axis objective (SAO) situated along the optical axis for focusing the incident laser beam along a slow axis

Methodology Applied

Scientific EffectOptical focusing: Lens

Data Source

PatentUS10761276B2Passively aligned crossed-cylinder objective assembly

Publication Date: 2020.09.01 NLIGHT INC

AI summary

A cross-cylinder objective assembly includes a fast axis objective (FAO) situated along an optical axis for focusing an incident laser beam along a fast axis, a slow axis objective (SAO) situated along the optical axis for focusing the incident laser beam along a slow axis, and a lens cell having fast and slow axis objective receiving portions for registering the FAO and SAO at a predetermined spacing along the optical axis.