Optical Combiner for Flow Cytometer Laser Beam Alignment

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Solution Overview

Problem

Flow cytometers face challenges in combining multiple laser beams efficiently due to space constraints and limitations in existing technologies, such as the use of expensive fiber optic cables that do not efficiently transmit UV radiation, and movable mirrors that can only use a single laser at a time, leading to issues with focal points and beam divergence.

Innovation Solution

An optical combiner system that combines two or more laser beams into a collinear beam using a dichroic beam combiner, beam size adjuster, and focusable beam shaping optics with cylindrical lenses, allowing for precise adjustment of beam size and convergence/divergence to focus both beams at the same location on a fluid stream, enabling the use of additional lasers at different wavelengths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If fiber optic cables are used to combine laser beams, then beam combination is achieved, but UV radiation transmission efficiency deteriorates

Engineering Contradiction:
Improvebeam combination capabilityVSAvoidUV radiation transmission efficiency
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent merges multiple laser beams spatially by combining them into a single optical path using beam combining optics, allowing simultaneous transmission of multiple wavelengths including UV without the transmission losses associated with fiber optic cables. This direct optical combining approach eliminates the need for fiber coupling that causes UV energy loss.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of operation

If movable mirrors are used to select laser beams, then single laser operation is achieved, but multi-laser functionality deteriorates

Engineering Contradiction:
Improvesingle laser operationVSAvoidmulti-laser functionality
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent implements a universal optical system where the beam combining optics can simultaneously handle multiple laser wavelengths (including UV, visible, and infrared) through a single optical path. The system is designed to accept and combine beams from multiple laser sources with different wavelengths, enabling multi-laser functionality while maintaining ease of operation through a unified optical architecture.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Manufacturing precision

If multiple laser beams are focused separately, then individual beam focusing is achieved, but space requirements deteriorate

Engineering Contradiction:
Improveindividual beam focusingVSAvoidspace requirements
Core Design Contradiction:
Manufacturing precisionVSArea of stationary object

Solution Approach 1:

The patent merges multiple laser beams into a single collinear optical path using beam combining optics, allowing all beams to be focused at a common location on the fluid stream. This approach eliminates the need for separate focusing systems for each laser, significantly reducing the space required for the optical system while maintaining precise focusing capability for all wavelengths.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of operation

If beam size adjusters are added to each laser path, then beam size control is achieved, but device complexity deteriorates

Engineering Contradiction:
Improvebeam size controlVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent implements a universal beam size control mechanism where adjustable beam combining optics serve multiple functions: they combine multiple laser beams, control beam sizes, and adjust convergence/divergence for all lasers simultaneously. This multi-functional approach provides beam size control capability while avoiding the need for separate adjusters for each laser path, thereby reducing overall device complexity.

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 solution allows for the efficient combination and focusing of multiple laser beams at the same location, increasing the power density and flexibility of flow cytometers, reducing space requirements, and enabling the detection of multiple markers without the limitations of fiber optic cables or movable mirrors.

Implementation Method 1

a dichroic beam combiner (110) that combines a first laser beam (102) and a second laser beam (104) into a collinear beam

Methodology Applied
Scientific EffectDichroic reflection: Dichroic Filter

Implementation Method 2

focusable beam shaping optics (112) that focus the combined, substantially collinear beam so that a focal point of the combined, substantially collinear beam is located on the stream (118)

Methodology Applied
Scientific EffectOptical focusing: Lens

Data Source

PatentEP2567204B1Optical combiner for combining multiple laser beams in a flow cytometer
Publication Date: 2021.12.29 BIO RAD LABORATORIES INC
  • EP2567204B1 patent drawingFigure 1
  • EP2567204B1 patent drawingFigure 2
  • EP2567204B1 patent drawingFigure 3

AI summary

Disclosed is an optical combiner for combining multiple laser beams in a flow cytometer. A dichroic beam combiner is used to combine a second laser beam with a first laser beam so that the two beams are collinear. A beam size adjuster is utilized to adjust the size and convergence/divergence of the second laser beam so that both laser beams focus in a vertical direction at the same location on a stream in the flow cytometer. A cylindrical lens with a vertically oriented axis in the focusable beam shaping optics can also be adjusted to adjust the location of the focus point of the two beams in the horizontal direction. Alignment is maintained with the opto-mechanical adjustments made on one laser beam relative to the other laser beam path. Additional beams can also be added to the optical path.