RU2535586C1 - Medium-magnification plan-apochromatic high-aperture microlens - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: microlens comprises five series-arranged components. The first component is a positive meniscus, the convex side of which faces the image space. The second component is a positive meniscus, which is glued from a biconvex lens and a positive meniscus whose convex side faces the image space. The third component is a positive triple-glued component which consists of two positive lenses with a biconcave lens in between, wherein the second positive lens is plane-convex, wherein the flat surface is mated with the intermediate image of the entrance pupil and faces the image plane, and has behind it an additional plane-convex lens facing the object space with its flat side. The fourth component is a positive lens which is glued from a negative meniscus whose concave side faces the image space and a biconvex lens. The fifth component is a negative meniscus whose concave side faces the object space and is glued from a biconcave lens and a biconvex lens.

EFFECT: higher output numerical aperture while maintaining plan-apochromatic correction, corrected chromatism of magnification and a larger linear image field.

2 cl, 1 dwg, 1 app, 1 tbl

Description

The present invention relates to optical instrumentation, namely, microscope lenses, and can be used for visual observation, output to a TV camera and photographing low-contrast microscopic structures that are at the limit of the resolution of light microscopes in natural light, luminescence light, in polarized light, the method of bright field, dark field, phase contrast, etc.

A planochromatic microscope objective [1] is known that contains five components, the first of which is a negative meniscus convex into the image space, the second is a single biconvex lens, the third is three-glued from two biconvex lenses with a biconcave lens located between them, and the fourth is a single biconvex lens, the fifth is a double-glued meniscus convex to the object, consisting of a biconvex and biconcave lens.

The lens has plan-chromatic correction, a large linear field of the image with corrected chromaticity of magnification.

But its input numerical aperture is not high enough and amounts to 40 × 0.75.

The closest technical solution to the claimed invention is a planochromatic lens of a large magnification microscope [2]. The lens contains five components, the first of which is a positive meniscus convex into the image space, the second component is a negative meniscus convex into the image space, glued from a negative biconcave and positive biconvex lenses, the third component is a positive three-glued lens from two positive biconvex lenses between which a negative biconcave lens is placed, the fourth is a positive two-lensed lens from a positive lens a convex convex lens and a negative meniscus convex to the image space, the fifth is a negative two-glued meniscus convex to the object space, glued from a positive biconvex and negative biconcave lens.

The lens has a high input aperture (63 × 0.9) and planochromatic correction, a high linear field of the image, magnification chromaticity is fixed.

But its output numerical aperture is small (only 0.0143).

The main task to which the invention is directed is to increase the output numerical aperture while maintaining planochromatic correction, corrected chromaticity of magnification, and a large linear image field.

The problem is solved using the proposed planochromatic high-aperture medium-magnification micro lens, which, like the prototype, contains five components in series, the first of which is made in the form of a positive meniscus convex to the image space, the second component is made in the form of a positive double-glued lens, the third positive a three-glued component consisting of two positive lenses with a negative biconcave lens placed between them, the fourth component is made in the form of a positive double-glued lens, and the fifth component is made in the form of a negative double-glued meniscus.

Unlike the prototype, the positive two-glued lens of the second component is made in the form of a biconvex positive lens and a positive meniscus convex into the image space, in the third positive component, the second positive lens is made convex in which the flat surface is aligned with the intermediate image of the entrance pupil and faces the image space , and behind it is additionally placed a positive plano-convex lens facing the flat space into the volume of one positive lens dvuskleennaya fourth component is formed as a negative meniscus facing concavity in the image space, and a biconvex positive lens and a negative meniscus dvuskleeny fifth component concavity facing in the object space and is made of a biconcave negative lens and a biconvex positive.

In addition, the positive meniscus of the second component, the negative meniscus of the fourth component and the biconvex lens of the fifth component are made of a material with a dispersion coefficient satisfying the condition 22≤ν _d ≤25, and the refractive index is 1.8≤n _d ≤1.87.

The essence of the invention lies in the fact that the implementation of the second component is a positive two-domed one from a positive biconvex lens and a positive meniscus convex into the image space, the third component is three-glued, having the last surface is flat, coinciding with the actual intermediate image of the entrance pupil, with an additionally placed positive plane-convex lens, the fourth component is positive, glued from the negative meniscus facing interior space of the object, and the positive biconvex lens, the fifth component, with a negative biconcluded meniscus, turned concavity into the object space, containing biconcave negative and biconvex positive lenses, it was possible to significantly increase the output numerical aperture while maintaining the planned correction, while it has a significant linear image field ( 2y '= 25 mm), and there is a real plane of the intermediate image of the entrance pupil, necessary for studies using the phase method contrast, and the choice of glass material of the above lenses with the indicated dispersion coefficients and refractive indices provided apochromatic correction and corrected chromaticity of magnification.

Based on the foregoing, we can conclude that the new set of essential features of the invention allowed us to obtain a technical result consisting in increasing the output numerical aperture by 1.5 times, due to which the information capacity of the image was significantly increased while maintaining planochromatic correction, a wide linear image field and corrected chromaticity of magnification and was ensured the possibility of conducting research using the phase contrast method.

The proposed planochromatic high-aperture medium-magnification micro lens is illustrated by the drawing, in which Fig. 1 shows its optical scheme, as well as by the Appendix, which gives the design parameters and aberration releases.

The inventive planochromatic high-aperture medium-magnification micro lens contains five components.

The first component I contains a positive meniscus 1, convex in the image space.

The second positive component II is glued from a positive biconvex lens 2 and a positive meniscus 3, convex to the image space.

The third component III contains a positive three-glued of positive biconvex 4 and plano-convex 5, the flat side facing the image space, with a negative biconcave 6 placed between them and a single positive flat-convex 7 lens.

The fourth positive component IV is glued from the negative meniscus 8, turned concavity into the image space, and the positive biconvex lens 9.

The fifth component V is the negative meniscus, turned concave into the space of the object, double-glued from a biconcave negative lens 10 and a biconvex positive lens 11.

The proposed lens works as follows.

The lens works with a tube lens f '= 200 mm.

Rays from the object of observation located in the front focal plane of the micro-lens pass through the first I and second II components, the positive meniscus 1 and the positive double-glued lens from the positive biconvex lens 2 and the positive meniscus 3, forming an imaginary enlarged image, introducing negative spherical aberration, position chromatism and increases to coma, astigmatism and curvature.

Next component III - lenses 4, 5, 6, and 7 form an imaginary enlarged image, completely correcting astigmatism and curvature, reducing spherical aberration, chromaticity of position and magnification, to whom.

Component IV - lenses 8 and 9 build a reduced real image of the object in the focal plane of component V, correcting spherical aberration, chromaticity of position and magnification, reduces coma.

Component V - lenses 10 and 11 transfers the image of the object to infinity, forming a planochromatic high-contrast image of the object.

According to the proposed scheme, a micro lens with a magnification of 40 ^x , a numerical aperture of 0.85, a linear image field of 25 mm, and an output numerical aperture 1.5 times larger than the prototype is implemented (in the prototype 0.0143, in the claimed technical solution 0.02125).

Table 1 presents the Strehl number, which characterizes the image quality of the micro-lens for the relative values of the image values.

Table 1 Rel image value Strehl number one 0.6 0.866 0.72 0.707 0.81 0.5 0.85 0 0.9

INFORMATION SOURCES

1. USSR author's certificate No. 1658114, IPC: G02B 21/02, publ. 06/23/1991 g.

2. USSR Author's Certificate No. 1485184, IPC: G02B 21/02, publ. 06/07/1987 - a prototype.

Claims (2)

1. Plano-chromatic high-aperture medium-magnification micro lens containing five components in series, the first of which is made in the form of a positive meniscus convex to the image space, the second component is made in the form of a positive double-glued lens, the third positive three-glued component, consisting of two positive lenses with between them a negative biconcave lens, the fourth component is made in the form of a positive double-glued lens, and the heel a component made in the form of a negative double-glued meniscus, characterized in that the positive double-glued lens of the second component is made in the form of a biconvex positive lens and a positive meniscus convex into the image space, in the third positive component the second positive lens is made convex in which the flat surface is aligned with intermediate image of the entrance pupil and faces the image space, and behind it is additionally placed a positive plane a convex lens facing the space of the object with a flat side, the positive two-glued lens of the fourth component is made in the form of a negative meniscus turned concavity into the image space, and a positive biconvex lens, and the negative two-glued meniscus of the fifth component is turned concavity into the object space and made of biconcave negative and biconvex positive lenses. 2. A plano-chromatic high-aperture medium-magnification micro lens according to claim 1, characterized in that the positive meniscus of the second component, the negative meniscus of the fourth component and the biconvex lens of the fifth component are made of a material with a dispersion coefficient satisfying the condition 22≤ν _d ≤25, and the refractive index has value 1.8≤n _d ≤1.87.

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