Anamorphotic telescope

Patent metadata

Field	Value
Publication number	US-9304300-B2
Application number	US-201113816531-A
Country	US
Kind code	B2
Filing date	Aug 12, 2011
Priority date	Aug 12, 2010
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

An anamorphotic telescope has mutually different magnification along directions of minimum and maximum magnification in an image plane. A spectroscope with an elongated input slit directed along one of the directions of maximum and minimum magnification may be located in the image plane. The anamorphotic telescope has a first and second reflector lens with mutually different first and second radii of curvature in directions (y, x) that optically correspond to directions of minimum and maximum magnification. At least one of the first and second reflector lens has a variable radius of curvature in one direction (x), which varies as a function of position in the other direction (y), the variable radius of curvature decreasing in a direction of the angle from the view direction to the light directed by the first reflector lens to the second reflector lens.

First claim

The invention claimed is:

1. An anamorphotic telescope, having mutually different magnification along directions of minimum and maximum magnification in an image plane, the anamorphotic telescope comprising a first and second reflector lens, the first reflector lens being oriented to direct light from a view direction of the telescope to the second reflector lens at an angle to the view direction, the second reflector lens being oriented to reflect light from the first reflector lens to the image plane, each of the first and second reflector lens comprising a reflective surface having a shape with mutually different first and second radii of curvature in first and second directions (y, x) that optically correspond to different ones of the directions of minimum and maximum magnification in the image plane respectively, wherein at least one of the first and second reflector lens has a variable radius of curvature in the second direction (x), which varies as a function of position in the first direction (y), the variable radius of curvature decreasing continually over said at least one of the first and second reflector lens in the direction of a first direction component of displacement from points along the view direction to points along a path of the light directed by the first reflector lens to the second reflector lens.

2. An anamorphotic telescope according to claim 1 , comprising a spectrometer with an elongated opening slit located in the image plane, the spectrometer being configured to resolve respective spectra at different positions along a direction of longest extent of the slit respectively, the direction of longest extent being aligned along the one of the directions of minimum and maximum magnification that corresponds to the second direction.

3. An anamorphotic telescope according to claim 2 , wherein the direction of longest extent is aligned along the direction of minimum magnification.

4. An anamorphotic telescope according to claim 2 , wherein a deviation between the view direction and an optical axis of between the first and second reflector lens is aligned with the first direction.

5. An anamorphotic telescope according to claim 1 , wherein the variable radius of curvature has a component of variation that is anti-symmetric under mirroring with respect to a symmetry plane containing the second direction and the optical axis between the first and second reflector lens, the anti-symmetric variation of an inverse of the second radius of curvature of the at least one of the first and second reflector lens lying in a range between a value
1/ Rxo and 1/ Rxo* (1 +2 *ade*ay* (0.26225 *Q −0.05 −0.27311) Rxo 2 /( Mx*Ry ))

wherein Q is a ratio between magnifications Mx and My of the anamorphotic telescope in the second and first directions defined as distance in the image plane per radian object direction difference, Rxo is a basic constant radius of curvature necessary for imaging in the image plane, Ry is the radius of curvature in the first direction, “ade” is the angle of the direction of incidence and ay is an angle between the optical axis between the first and second reflector lens and a line from a centre of the curvature of the at least one of the first and second reflector lens in the first direction and a point on the first reflector lens for which the radius of curvature is defined.

6. An anamorphotic telescope according to claim 5 , wherein the anti-symmetric variation of an inverse of the second radius of curvature of the at least one of the first and second reflector lens lying varies according to
1/ Rxo* (1+ade*ay*(0.26225* Q −0.05 −0.27311) Rxo 2 /( Mx*Ry )).

7. An anamorphotic telescope according to claim 1 wherein the second radius of curvature varies with position at least in that one of the first and second reflector lens that is closest to virtual images formed between the first and second reflector lens.

8. An anamorphotic telescope according to claim 1 , comprising an aperture stop located between the first and second reflector lens at a distance from the second reflector lens that equals a focus distance of the second reflector lens for object lines that extend along the direction.

9. An anamorphotic telescope according to claim 1 , comprising a spectrometer configured to receive light from the second reflector lens through an elongated slit with a longest direction extending in the second direction.

10. An anamorphotic telescope according to claim 5 , wherein a first magnification in the first direction is larger than a second magnification in the second direction.

11. An anamorphotic telescope according to claim 7 , wherein a ratio between the maximum and minimum magnification is at least 1.2.

12. An anamorphotic telescope according to claim 1 , comprising a polarization scrambler located between the first and second reflector lens.

13. An anamorphotic telescope according to claim 1 , wherein the first and second reflector lens are relatively oriented so that an optical path through the telescope from the view direction to the first reflector lens, from the first reflector lens to the second reflector lens and from the second reflector lens to the image plane is entirely perpendicular to said second direction (x).

14. A method of imaging an object, comprising viewing the object with the anamorphotic telescope according to claim 1 , and moving the anamorphotic telescope in a direction perpendicular to said second direction (x) during imaging.

15. An anamorphotic telescope, having mutually different magnification along directions of minimum and maximum magnification in an image plane, the anamorphotic telescope comprising a first and second reflector lens, the first reflector lens being oriented to direct light from a view direction of the telescope to the second reflector lens at an angle to the view direction, the second reflector lens being oriented to reflect light from the first reflector lens to the image plane, each of the first and second reflector lens comprising a reflective surface having a shape with mutually different first and second radii of curvature in first and second directions (y, x) that optically correspond to the directions of minimum and maximum magnification in the image plane respectively, wherein at least one of the first and second reflector lens has a variable radius of curvature in the second direction (x) that only decreases in the direction of a first direction component of displacement from points along the view direction to points along a path of the light directed by the first reflector lens to the second reflector lens.

Assignees

• Visser Huibert
• Kruizinga Borgert
• Nijkerk Michiel David
• TNO

Inventors

• Visser Huibert
• Kruizinga Borgert
• Nijkerk Michiel David

Classifications

• G02B23/06

  having a focussing action, e.g. parabolic mirror · CPC title

• G02B17/0621 Primary

  off-axis or unobscured systems in which not all of the mirrors share a common axis of rotational symmetry, e.g. at least one of the mirrors is warped, tilted or decentered with respect to the other elements · CPC title

• G02B13/12 Primary

  with variable magnification · CPC title

• G02B13/08

  Anamorphotic objectives · CPC title