Koehler Integrator Layout for Wavelength-Independent Spot Arrays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional Koehler integrators are limited in generating a uniform array of excitation spots at multiple wavelengths and suffer from power loss, making them unsuitable for multi-focal confocal microscopy and other applications requiring efficient illumination.
Innovation Solution
A Koehler integrator device comprising a collimating lens, planar micro-lens arrays, and a Fourier lens, with a third micro-lens array arranged in the Fourier lens front focal plane to create a wavelength-independent array of light spots, ensuring telecentric illumination and high power efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a single mode laser beam with Gaussian intensity profile is used to generate an array of excitation spots, then the excitation spots can be created, but the relative intensities of the excitation spots follow a Gaussian distribution causing significant intensity variation across the field of view and significant power loss when only the central part is used
Solution Approach 1:
The patent segments the single Gaussian beam into multiple discrete excitation spots using a micro-lens array, where each micro-lens focuses a portion of the beam to create an individual spot. This segmentation allows the use of the entire beam profile rather than just the central part, reducing power loss while maintaining intensity uniformity across all spots through the engineered lens array geometry
Solution Approach 2:
The patent applies local quality by designing micro-lenses with varying focal lengths or apertures across the array to compensate for the Gaussian intensity distribution. Each micro-lens is locally optimized to produce spots of equal intensity, with lenses at the periphery having different properties than those at the center, thereby achieving uniform illumination across the entire field of view
2Illumination intensity
If a conventional Koehler integrator is used to homogenize the light beam, then the intensity distribution can be improved, but the device complexity increases and power efficiency decreases
Solution Approach 1:
The patent extracts and eliminates the unnecessary components from the conventional Koehler integrator design, retaining only the essential micro-lens array and collimating lens combination needed to achieve beam homogenization and uniform spot generation. This simplification removes redundant optical elements while preserving the core functionality of creating uniform illumination
Solution Approach 2:
The patent designs a multi-functional optical system where the micro-lens array simultaneously performs beam homogenization, spot generation, and intensity equalization that would traditionally require separate components. The integrated design achieves multiple objectives (homogenization, uniform spot array creation, and wavelength independence) within a single compact device structure
3Adaptability or versatility
If a conventional Koehler integrator is used to create an array of excitation spots, then the spots can be generated, but the spots are not independent of wavelength and power efficiency is reduced
Solution Approach 1:
The patent employs parameter changes by carefully selecting and optimizing the focal lengths, pitch, and aperture sizes of the micro-lenses to achieve wavelength-independent spot generation. The geometric parameters of the micro-lens array are engineered so that spots of equal size and intensity are formed across a broad spectral range, eliminating the wavelength dependence inherent in conventional designs while maintaining high power efficiency
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 enables the generation of a uniform array of light spots with equal intensities, independent of wavelength, improving power efficiency and reducing illumination artifacts in multi-focal confocal microscopy and other applications.
Implementation Method 1
a collimating lens (11) adapted for collimating a light field created by a light source device (110)
Implementation Method 2
The micro-lens arrays (12, 13, 15) are arranged for relaying portions of the collimated light field through separate micro-lens array imaging channels
Implementation Method 3
Each micro-lens of the first micro-lens array (12) has a common micro-lens axis with a related micro-lens of the second micro-lens array (13) (mutual alignment of the micro-lens arrays). The first and second micro-lens arrays (12, 13) are arranged for relaying portions of the collimated light field through separate micro-lens array imaging channels
Implementation Method 4
a Fourier lens (14) superimposing light from all imaging channels in a front focal plane of the Fourier lens (14)
Implementation Method 5
The third micro-lens array (15) is arranged in the front focal plane of the Fourier lens (14) for creating a wavelength independent array of light spots
Data Source
Figure 1~3
Figure 4
Figure 5
AI summary
A Koehler integrator device (10) comprises a collimating lens (11) being arranged for collimating a light field created by an incoherent or partially coherent light source, a pair of planar first and second micro-lens arrays (12, 13) being arranged for relaying portions of the collimated light field along separate imaging channels, wherein all micro-lenses of the first and second micro-lens arrays (12, 13) have an equal micro-lens focal length and pitch and the micro-lens arrays (12, 13) are arranged with a mutual distance equal to the micro-lens focal length, and a collecting Fourier lens (4) having a Fourier lens diameter and a Fourier lens focal length defining a Fourier lens front focal plane and a Fourier lens back focal plane, wherein the Fourier lens (14) is arranged for superimposing light from all imaging channels in the Fourier lens front focal plane and wherein the second micro-lens array (13) is arranged in the Fourier lens back focal plane, wherein a third micro-lens array (15) is arranged in the Fourier lens front focal plane for creating a wavelength independent array of illumination spots. Furthermore, a confocal microscope apparatus, which comprises the Koehler integrator device, and a method of using the confocal microscope apparatus are described..