RU2486552C1 - Plan-apochromatic high-aperture microlens - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: first component I with optical power φ_I is in form of a frontal meniscus whose concave surface faces the object space, and a biconvex lens. The second component II with optical power φ_II consists of a biconvex lens and a biconcave lens glued together, a biconvex lens with optical power φ_II5 and a glued lens with optical power φ_II6.7, consisting of a diverging meniscus whose concave surface faces the image space, and a biconvex lens. The third component III with optical power φ_III is in form of a meniscus whose concave surface faces the object space, glued from a converging meniscus and a diverging meniscus. The ratio of optical power values of the lenses φ_II5,6,7 and the lens overall φ_l satisfies the condition: $$\mathrm{0,3}\le \frac{{\phi }_{II\mathrm{5,6,7}}}{{\phi }_{\text{I}}}\le \mathrm{0,7.}$$

The biconvex lens with optical power φ_II5 and the biconvex lens of the glued lens of the second component are made of material with dispersion coefficient 58<v_d<95.2. The diverging meniscus of the glued lens of the second component is made of material with dispersion coefficient 57<V_d<60.

EFFECT: improved mono and chromatic aberrations of axial and off-axis beams and a larger entrance aperture.

2 cl, 1 dwg, 1 app

Description

The present invention relates to the field of microscopy and can be used for visual observation and photographing of low-contrast microscopic structures that are at the limit of the resolution of light microscopes in natural light, in the light of visible luminescence, in polarized light by the method of bright field, dark field, phase contrast, etc.

A planochromatic microscope objective is known [1], containing five components, the first of which is a negative meniscus convex to the image, the second is a single biconvex lens, the third is an glued component containing two positive biconvex lenses, with a negative biconcave lens placed between them, the fourth the component is a single positive biconvex lens and the fifth component is a double-glued meniscus convex to the object.

The lens has high image quality over the entire linear field of view (2y '= 25 mm), but its output aperture is not high enough (0.0187).

The closest technical solution to the present invention is a planachromatic high aperture micro lens [2] containing three components, the first of which is made along the beam in the form of a frontal meniscus facing concavity to the space of the object and a biconvex positive lens, the second contains a biconvex positive lens and glued from a biconvex and biconcave lenses, and the third component consists of two positive biconvex lenses.

The micro lens has a rather high input aperture (20 × 0.65), a planned correction, but insufficiently corrected chromatism (achromatic lens).

Modern models of microscopes require a high-aperture plano-chromatic micro-lenses, which have improved correction of monochromatic and chromatic aberrations on the axis and linear field of view.

The main task to be solved by the alleged invention is aimed at improving mono and chromatic aberrations of the axial and off-axis bundles, as well as increasing the input aperture.

To solve this problem, we proposed a planochromatic high-aperture micro lens, which, like the prototype, contains three components, the first of which I with the optical power φ _{I is} made in the form of a front meniscus facing concavity to the space of the object and a biconvex positive lens, the second component II with optical a power of φ _II , consisting of a bonded of positive biconvex and biconcave negative lenses, and a third component III with an optical power of φ _III containing two lenses.

In contrast to the prototype, in the second component with optical power φ _II behind the glued lens, consisting of a positive biconvex and biconcave negative lenses, a positive biconvex lens with optical power φ _II5 and a _bonded lens with optical power φ _II6.7 , consisting of a negative meniscus facing concavity to the image space, and a positive biconvex lens, and the lens of the third component with optical power φ _{III is} made in the form of a meniscus facing concavity to the space of objects the one glued from the positive and negative menisci facing concavity to the space of the object, while the ratio of the optical powers of the lens φ _II5,6,7 and the lens as a whole φ _about satisfy the following conditions:

, кроме того, положительная двояковыпуклая линза с оптической силой φ_II5 и положительная двояковыпуклая линза склеенной линзы второго компонента выполнены из материала с коэффициентом дисперсии, удовлетворяющим следующим условиям: 58<ν_d<95,2, а отрицательный мениск, обращенный вогнутостью к пространству изображения склеенной линзы второго компонента, выполнен из материала с коэффициентом дисперсии, удовлетворяющим условию: 57<ν_d<60. $$0.3\le \frac{{\varphi }_{II\mathrm{5,6,7}}}{{\varphi }_{\mathrm{about}b}}\le 0.7$$

in addition, a positive biconvex lens with an optical power of _{и II5} and a positive biconvex lens of a glued lens of the second component are made of a material with a dispersion coefficient satisfying the following conditions: 58 <ν _d <95.2, and a negative meniscus facing a concavity to the glued image space the lens of the second component is made of a material with a dispersion coefficient satisfying the condition: 57 <ν _d <60.

In addition, the front meniscus of the first component is made of material with a dispersion coefficient of 42 <ν _d <48 and a refractive index of n _d ≥1.8, the optical forces of the menisci of the third component φ _III8 and φ _III9 are related by the following relation:

, где $${\varphi }_{III8}=\frac{1}{f_8^{\text{'}}}$$

; $${\varphi }_{III9}=\frac{1}{f_9^{\text{'}}}$$

; f' - фокусное расстояние. $$0.25\le \left|\frac{{\varphi }_{III8}}{{\varphi }_{III9}}\right|\le 0.75$$

where $${\varphi }_{III8}=\frac{\mathrm{one}}{f_8^{\text{'}\text{'}}}$$

; $${\varphi }_{III9}=\frac{\mathrm{one}}{f_9^{\text{'}\text{'}}}$$

; f 'is the focal length.

The essence of the alleged invention lies in the fact that such a planochromatic high-aperture micro lens made it possible to improve the correction of mono and chromatic aberrations of axial and off-axis beams, due to which planochromatic correction was achieved. In addition, the input aperture is increased.

Thus, a technical result has been achieved, consisting in increasing the input aperture and achieving planochromatic correction.

The present invention is illustrated (Fig. 1), which shows an optical diagram of a planochromatic high-aperture micro lens, as well as an application (Fig. 2), in which structural parameters and graphs of a frequency-contrast characteristic are given.

A planaprochromatic high-aperture micro lens contains three components, the first of which I with optical power φ _{I is} made in the form of a frontal meniscus 1 facing concavity to the space of the object and a biconvex positive lens 2, the second component II with optical power φ _II consists of glued from a positive biconvex lens 3 and a biconcave negative lens 4, while a positive biconvex lens 5 with optical power φ _II5 and a _bonded lens with optical power φ _II6 are placed behind the glued lens along the beam _{; 7} , consisting of a negative meniscus 6, facing concavity to the image space, and a positive biconvex lens 7.

.The lenses of the third component with optical power φ _{III are} made in the form of a meniscus facing concavity to the space of the object glued from positive 8 and negative 9 menisci facing concavity to the space of the object, while the ratio of the optical powers of the lens φ _II5,6,7 and the lens, in In general, fob satisfy the following conditions: $$0.3\le \frac{{\varphi }_{II\mathrm{5,6,7}}}{{\varphi }_{\mathrm{about}b}}\le 0.7$$

.

A positive biconvex lens 5 with an optical power of _{II II5} and a positive biconvex lens 7 of the glued lens of the second component are made of a material with a dispersion coefficient satisfying the following conditions: 58 <ν _d <95.2, and a negative meniscus 6, facing the concavity to the image space of the glued lens the second component is made of material with a dispersion coefficient satisfying the condition: 57 <ν _d <60.

The front meniscus 1 of the first component is made of material with a dispersion coefficient of 42 <ν _d <48 and a refractive index of n _d ≥1.8, the optical forces of the menisci of the third component φ _III8 and φ _III9 are related by the following relation:

, $$0.25\le \left|\frac{{\varphi }_{III8}}{{\varphi }_{III9}}\right|\le 0.75$$

,

; $${\varphi }_{III9}=\frac{1}{f_9^{\text{'}}}$$

; f' - фокусное расстояние.Where $${\varphi }_{III8}=\frac{\mathrm{one}}{f_8^{\text{'}\text{'}}}$$

; $${\varphi }_{III9}=\frac{\mathrm{one}}{f_9^{\text{'}\text{'}}}$$

; f 'is the focal length.

The proposed planochromatic high-aperture micro lens works as follows.

The micro lens works with a tube lens with a focus of 160 mm.

The front meniscus 1, facing concavity to the space of the object, together with the biconvex lens 2, builds an enlarged imaginary image of the object with moderate values of spherical aberration, coma, astigmatism and curvature and significant chromaticity of magnification (HR).

The second component II projects the image of the object with an additional increase in the focal plane of the third component III, introducing negative spherical aberration, positive coma and astigmatism, partially compensating for the chromaticity of the position and magnification.

Component III projects the image of the object to infinity, compensating for residual spherical aberration, chromaticity of position and magnification, astigmatism and curvature.

In accordance with the proposed technical solution, as a specific example, a planochromatic high-aperture micro-lens was calculated with a magnification of 20 times, an input aperture of 0.7, and a linear image field of 25 mm.

The lens has high image quality over the entire linear field of view 2y '= 25 mm.

Thus, over the entire linear field of view of the lens, the Strehl ratio is from 0.91 in the center to 0.51 at the edge of the field.

Such large values cause a high concentration of energy in the center of the diffraction spot, and, consequently, a high image contrast over the entire field of observation.

Chromatic difference of magnifications in the HRU lens ≤0.3%.

The calculation results are given in the appendix.

INFORMATION SOURCES

1. Russian Federation, patent for the invention No. 1658114, IPC: G02B 21/02, publ. 06/23/1991 g.

2. Russian Federation, patent for utility model No. 37239, IPC: G02B 21/02, publ. 04/10/2004 - the prototype.

Micro lens focal length, 8.0 mm:

Increase, krat twenty Input aperture 0.7 Linear field of view, mm 25.0 The position of the entrance pupil, mm Infinite Image Diameter, mm: 25.0 Spectral range, nm 0.43583-0.6438

Design parameters of the optical system Radii of curvature Axis distances n _d Coeff. Dispersions V _d 0 0 0 0.17 1.5148 60.61 0 1.0144 1.0 -3.221 3.95 1.804 46.5 -5.495 0.18 1.0 83.56 4.7 1.6126 57.96 -7.727 0.12 1.0 27.54 5.65 1.43387 95.3 -6.252 1.5 1.6541 39.7 37.76 0.27 1.0 15.992 6 1.43387 95.3 -15.992 0.1 1.0 50.58 1.5 1.5400 59.6 12.417 6.5 1.43387 95.3 -16.943 7.9 1.0 -7.079 3 1.7552 27.5 -7.145 2.1 1.61265 57.96 -13.0620 120 1.0 Tube lens -21.73 3 1.5689 55.87 -121.34 6.5 1.6990 30.2 -28.64 9.7 1.0 -671.4 3 1.7400 28.17 46.56 3.5 1.6200 36.3 30.55 8.7 1.6280 59.45 -79.07 10 one. 0 78.3 1.5164 64.2 0 12.8 1.0 - 0 105 1.5689 55.87 0 45.95 Pl-st fig.

Claims (2)

1. Plano-chromatic high-aperture micro lens containing three components, the first of which I with optical power φ _{I is} made in the form of a front meniscus facing concavity to the space of the object and a biconvex positive lens, the second component II with optical power φ _II , consisting of glued from positive biconvex and biconcave negative lenses, and the third component III with optical power φ _III , containing two lenses, characterized in that in the second component behind the glued lens, consisting of positively biconvex and biconcave negative lenses, a positive biconvex lens with optical power φ _II5 and a _bonded lens with optical power φ _II6,7 , consisting of a negative meniscus facing concavity to the image space, and a positive biconvex lens, and the lens of the third component are placed along the beam made in the form of a meniscus facing concavity to the space of the object glued from the positive and negative menisci facing concavity to the space of the object, while the optical ratio Sgiach forces φ _II5,6,7 lenses and lens as a whole _about cp satisfy the following conditions:
$$0.3\le \frac{{\phi }_{II\mathrm{5,6,7}}}{{\phi }_{\mathrm{about}b}}\le \mathrm{0.7,}$$

in addition, a positive biconvex lens with an optical power of _{и II5} and a positive biconvex lens of a glued lens of the second component are made of a material with a dispersion coefficient satisfying the following conditions: 58 <ν _d <95.2, and a negative meniscus facing concavity to the image space of the glued lens the second component is made of a material with a dispersion coefficient satisfying the condition: 57 <ν _d <60. 2. Plano-chromatic high-aperture micro lens according to claim 1, characterized in that the front meniscus of the first component is made of material with a dispersion coefficient of 42 <ν _d <48 and a refractive index of n _d ≥1.8, the optical forces of the menisci of the third component are φ _III8 and φ _III9 are connected by the following relation:
$$0.25\le \left|\frac{{\phi }_{III8}}{{\phi }_{III9}}\right|\le \mathrm{0.75,}$$

Where $${\phi }_{III8}=\frac{\mathrm{one}}{f_8^{\text{'}\text{'}}};$$

$${\phi }_{III9}=\frac{\mathrm{one}}{f_9^{\text{'}\text{'}}},$$

f 'is the focal length.

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