Immersion Microscope Objective Aberration Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional microscope objectives with high numerical aperture face difficulties in correcting aberrations such as spherical and chromatic aberrations without the use of special oils or cover glasses, limiting their ability to achieve high resolution and small evanescent light leakage in total internal reflection fluorescence microscopy (TIRFM).
Innovation Solution
An immersion microscope objective with a four-group configuration, including a first lens group with a positive refractive power, a second lens group with multiple cemented lenses, a third lens group with negative refractive power, and a fourth lens group with a concave surface, arranged in a specific order to correct Petzval sum, chromatic aberrations, coma, and astigmatism, while satisfying specific conditional expressions for numerical aperture and refractive indices to achieve high resolution and reduced evanescent light leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional high numerical aperture microscope objectives are used, then the numerical aperture can be increased, but aberrations such as spherical and chromatic aberrations cannot be corrected without special oils or cover glasses
Solution Approach 1:
The objective lens is divided into four distinct lens groups with specific arrangements. The first lens group includes a positive meniscus lens and cemented lens, the second lens group includes multiple cemented lenses, the third lens group includes a negative lens component, and the fourth lens group includes a lens component with a concave surface facing the object. This segmentation allows independent optimization of each group to correct specific aberrations while maintaining high numerical aperture.
Solution Approach 2:
Each lens group is designed with specific local optical properties and material characteristics. The meniscus lens in the first group has specific refractive index and Abbe number requirements, the cemented lenses in the second group have specific dispersion properties, and the negative lens in the third group has specific curvature characteristics. This local quality optimization enables targeted correction of different types of aberrations in different regions of the optical path.
2Measurement precision
If high numerical aperture is achieved, then resolution is improved, but evanescent light leakage increases
Solution Approach 1:
The patent optimizes specific optical parameters including the numerical aperture ratio (NAob/N0 between 0.986 and 0.995), the refractive index-product relationship (1/(N1×ν1) between 0.0095 and 0.015), and the curvature radii of various lens surfaces. These parameter changes are carefully controlled to achieve the optimal balance between high resolution and minimal evanescent light leakage, with the numerical aperture specifically set to 1.49 or higher.
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 objective achieves a numerical aperture of 1.49 or higher, enabling high-resolution observation with weak light and minimizing evanescent light leakage, effectively correcting aberrations and improving image quality in TIRFM.
Implementation Method 1
a first cemented lens consisting of a lens having a positive refractive power and a meniscus lens
Implementation Method 2
N0, a refractive index that an immersion liquid used for the microscope objective has for an e line
Data Source
AI summary
A immersion microscope objective includes: a first positive lens group that includes at least one positive single lens and a first cemented lens; a second positive lens group that includes a plurality of cemented lenses including a second cemented lens that is the closest to an object; a third negative lens group that includes a first lens component having a concave surface; and a fourth lens group that includes a second lens component that is the closest to the object, the second lens component having a concave surface, wherein the objective satisfies the following conditional expressions:0.986≤NAob/N0≤0.995 (1)0.0095≤1/(N1×ν1)≤0.015 (2)where NAob indicates a numerical aperture of the objective; N0, a refractive index that an immersion liquid has for an e line; N1, a refractive index that the meniscus lens has for the e line; ν1, an Abbe number that the meniscus lens has for a d line.