RU132572U1 - MIRROR LENS LENS - Google Patents

Abstract

Mirror-lens lens containing the main hyperboloidal mirror concave in the direction of the beam in series with the central hole, the secondary convex hyperboloidal mirror and the lens system with optical power φ made of three lenses mounted behind the main mirror, characterized in that the optical forces of the lenses and air the gaps satisfy the condition: where φ is the optical power of the mirror system consisting of the main and secondary mirrors; 0.5≤φ / φ≤0.71.0≤ | φ / φ | ≤2.02.0≤φ / φ≤3 , 00.12≤ | φd | ≤0.20.05≤ | φd | ≤0.15, where φ , φ, φ - optical powers of the first, second and third lenses; d, d are the distances between the first, second and third lenses, respectively.

Description

The proposed utility model relates to optical instrumentation, and can be used in the optical industry, and, in particular, in astronomical telescopes, and especially in the optoelectronic cameras of space telescopes, etc.

Mirror-lens lenses usually consist of a main concave mirror with a central hole, a secondary convex and lens corrector for field aberrations.

Spherical aberration and coma are corrected by aspherization of the main and secondary mirrors, giving them a hyperboloidal shape. Field aberrations - astigmatism and image curvature are corrected by the lens field aberration corrector (CPA), which is usually installed behind the main mirror in front of the focal plane.

Known mirror lenses containing a hyperbolic main mirror (GB) and a secondary mirror (VZ) and a single-lens CPA with an aspherical surface [1].

Such a corrector made it possible to correct astigmatism. To correct the curvature of the image, it was necessary to push the GB and the VZ. This led to a large central shielding factor ε = 0.57 and significant longitudinal dimensions: the distance d between the GB and WZ was 0.33f ' _o , where f' _o is the focal length of the entire lens, and, consequently, to an increase that is unacceptable for a space telescope masses.

The closest technical solution to the proposed utility model is a mirror-lens lens [2], which contains a main hyperboloidal mirror concave with a central hole, a secondary convex hyperboloidal mirror, and a lens system with optical power φ _L.c. made of two lens components separated by an air gap, containing three lenses, of which the first and second lenses are installed close to each other.

The disadvantage of this system is the limited angular field not exceeding 1.5 ° with a mean square wavefront deformation (RMS) ≤0.07 ÷ 0.08 λ.

The main task, which the utility model is aimed at, is to increase the angular field with diffraction-limited image quality in a wide spectral range and small longitudinal dimensions of the lens.

To solve this problem, a mirror-lens objective is proposed, which, like the prototype, contains a main hyperboloidal mirror concave with a central hole, a secondary convex hyperboloidal mirror, and a lens system with optical power φ _hp made of three lenses mounted behind the main mirror.

In contrast to the prototype, the optical power of the lenses and air gaps satisfy the condition:

,

,

where φ _z.s. - the optical power of the mirror system, consisting of the main and secondary mirrors;

0,5≤φ ₁ / φ _hp ≤0.7

1,0≤ | φ ₂ / φ _hp | ≤2.0

2.0≤φ ₃ / φ _HP ≤3.0

0.12≤ | φ _hp d ₁ | ≤0.2 0.05≤ | φ _hp d ₂ | ≤0.15, where φ ₁ , φ ₂ , φ ₃ are the optical forces of the first, second and third, d ₁ , d ₂ are the distances between the first, second and third lenses, respectively.

, где φ_з.с. - оптическая сила зеркальной системы, состоящей из главного и вторичного зеркал;The essence of the proposed utility model lies in the fact that, thanks to the proposed scheme for performing a mirror-lens lens, consisting of a hyperboloidal mirror concave with a central aperture and a convex hyperboloidal mirror and a lens system with optical power φ _hp mounted sequentially in the direction of the beam _. made of three lenses mounted behind the main mirror, while the optical power of the lenses and air gaps satisfies the condition:

where φ _z.s. - the optical power of the mirror system, consisting of the main and secondary mirrors;

0,5≤φ ₁ / φ _hp ≤0.7

1,0≤ | φ ₂ / φ _hp | ≤2.0

2.0≤φ ₃ / φ _HP ≤3.0

0.12≤ | φ _hp d ₁ | ≤0.2 0.05≤ | φ _hp d ₂ | ≤0.15, where φ ₁ , φ ₂ , φ ₃ are the optical forces of the first, second, and third, d ₁ , d ₂ are the distances between the first, second, and third lenses, respectively, and the correction of field aberrations of monochromatic and chromaticity increases in a wide spectral range with increased angular fields of the object.

In particular, the selected ratio of the optical forces and the distances d ₁ and d ₂ between the lenses makes it possible to correct the image curvature and astigmatism of the entire lens as a whole and thereby ensure diffraction-limited image quality at large angular fields of 2ω≥1.75 °.

The essence of the proposed utility model is illustrated in the drawing, where Fig. 1 shows the optical scheme of the lens and the Appendix, which shows the design parameters and optical characteristics of the lens.

The mirror-lens lens consists of a main hyperboloidal mirror 1 concave with a central hole, a secondary convex hyperboloidal mirror 2, and a lens system 3 with optical power φ _hp made of three lenses: from the first lens 4 with optical power φ ₁ , the second lens 5 with optical power φ ₂ , and the third lens 6 with optical power φ ₃ .

Optical power φ _hp from the lens system 3 and its lenses satisfy the condition:

; 0,5≤φ₁/φ_л.с.≤0,7; 1,0≤|φ₂/φ_л.с.|≤2,0; 2,0≤φ₃/φ_л.с.≤3,0, а расстояние d₁ между первой 4 и второй 5 линзами и d₂ между второй 5 и третьей 6 составляют:

; 0,5≤φ ₁ / φ _hp ≤0.7; 1,0≤ | φ ₂ / φ _hp | ≤2.0; 2.0≤φ ₃ / φ _HP ≤3.0, and the distance d ₁ between the first 4 and second 5 lenses and d ₂ between the second 5 and third 6 are:

0.12 / | φ _hp | ≤d ₁ ≤0.2 / | ft _hp |;

0.05 / | φ _hp | ≤d ₂ ≤0.15 / | φ _lp |.

The work of the proposed mirror-lens is as follows.

A parallel beam of light falls on the main concave mirror 1 and focuses in its focal plane located in front of the secondary convex mirror 2.

The secondary convex mirror 2, for which the imaginary object is an image of the object in the focal plane of the main concave mirror 1, depicts it in the focal plane of the mirror system, consisting of the main 1 and secondary 2 mirrors.

The lens system 3 transfers the image after the mirror system to the focal plane of the entire mirror-lens lens with a positive magnification, i.e. without wrapping the image.

The stated ratio of parameters and the obtained technical characteristics are given in the Appendix.

The rms wavefront strain RMS <0.07λ was obtained over the entire field, which corresponds to diffraction-limited image quality, with an angular field of 2ω≥1.75 °.

INFORMATION SOURCES

1. N.N. Michelson "Optics of astronomical telescopes and methods of its calculation", "Physics and mathematics", 1995, pp. 328-331.

2. Russian Federation, patent No. 2415451, IPC: G02B 17/06, 03/27/2011 - prototype.

Claims (1)

Mirror-lens objective, comprising a main hyperboloidal mirror concave in the direction of the beam in series with the central hole, a secondary convex hyperboloidal mirror and a lens system with optical power φ _hp made of three lenses mounted behind the main mirror, characterized in that the optical forces lenses and air gaps satisfies the condition: $$\frac{{\phi }_{l.\mathrm{from}}}{{\phi }_{s.\mathrm{from}}}=-7.5÷-\mathrm{8.5,}$$

where φ _z.s - the optical power of the mirror system, consisting of the main and secondary mirrors; 0.5≤φ ₁ / φ _hp ≤0.7 1,0≤ | φ ₂ / φ _hp | ≤2,0 2.0≤φ ₃ / φ _hp ≤3.0 0.12≤ | φ _hp d ₁ | ≤0.2 0.05≤ | φ _hp d ₂ | ≤0.15, where φ ₁ , φ ₂ , φ ₃ - the optical power of the first, second and third lenses; d ₁ , d ₂ - the distance between the first, second and third lenses, respectively.

Images