Multimode Diode Laser Beam Shaping for Flow Cytometry

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Solution Overview

Problem

Current flow cytometry equipment, particularly for sperm sorting, requires expensive and bulky ultraviolet wavelength excitation sources with high energy consumption, and existing solid-state and diode lasers fail to meet power, wavelength, and spatial uniformity requirements for high-resolution DNA content measurements.

Innovation Solution

A method and apparatus utilizing a multimode diode laser with beam shaping optics to produce a uniform spatial intensity beam profile, suitable for illuminating fluorescent dyes like Hoechst 33342, enabling differentiation of X- and Y-chromosome bearing sperm by modifying the multimode beam to achieve uniform spatial intensity characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of stationary object

If a multimode diode laser is used to reduce cost and size, then the device becomes smaller and cheaper, but the spatial intensity profile becomes highly irregular and variable

Engineering Contradiction:
Improvelaser system weightVSAvoidspatial intensity profile uniformity
Core Design Contradiction:
Weight of stationary objectVSStability of the object's composition

Solution Approach 1:

Beam shaping optics are introduced as an intermediary component between the multimode diode laser and the sample. These optics transform the irregular multimode beam profile into a uniform spatial intensity distribution, enabling the use of compact diode lasers while maintaining the measurement precision required for sperm DNA content analysis

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If laser power is increased to compensate for lower excitation efficiency at 370-380nm, then excitation power increases, but laser diode lifetime decreases due to premature component failure

Engineering Contradiction:
Improvelaser excitation powerVSAvoidlaser diode lifetime
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The system operates the laser diode at optimized current parameters that balance excitation power requirements with component longevity. By carefully controlling operating parameters and using beam shaping optics to maximize excitation efficiency, the system achieves sufficient fluorescence excitation while extending laser diode lifetime and avoiding premature failure

Inventive Principle:
Principle #35Parameter changes

3Power

If coupling losses are minimized to maintain full 200mW output, then laser power is preserved, but system complexity increases

Engineering Contradiction:
Improvelaser output powerVSAvoidoptical coupling system complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

Beam shaping optics serve as an intermediary that addresses both power preservation and system complexity. The optics are designed to efficiently couple the laser beam while shaping it for uniform intensity distribution, maintaining high excitation power without requiring overly complex optical coupling arrangements

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution allows for efficient and cost-effective high-resolution sorting of sperm cells by maintaining consistent laser power and improving excitation efficiency, achieving sufficient resolution to differentiate between X- and Y-chromosome bearing sperm.

Implementation Method 1

a multimode diode laser for producing a multimode beam along a beam axis that illuminates particles at the interrogation zone

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

The multimode beam may have a beam profile with variable spatial intensity characteristics and that beam profile may be modified with beam shaping optics in the beam axis

Methodology Applied
Scientific EffectOptical beam shaping: Lens

Implementation Method 3

illuminating fluorescent dyes, such as Hoechst 33342, with high resolution

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP3913354B1UV diode laser excitation in flow cytometry
Publication Date: 2023.12.20 XY INC
  • EP3913354B1 patent drawingFigure 1
  • EP3913354B1 patent drawingFigure 2
  • EP3913354B1 patent drawingFigure 3

AI summary

The present invention generally relates to a method and apparatus for exciting particles, and more specifically relates to analyzers or sorters for exciting fluorescently labeled particles with a multimode diode laser and the optics for making high resolution determinations from the multimode diode laser beam excitation.