Telescope baffle system

• US 5,189,554 A
• Filed: 09/30/1991
• Issued: 02/23/1993
• Est. Priority Date: 09/30/1991
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Huppi, Ernest R., Vanasse, George A.
• Primary Examiner(s): Ben, Loha
• Application Number:
  US07/771,378
• Time in Patent Office: 512 Days
• Field of Search: 359/601, 359/603, 359/399, 359/611, 359/613, 359/300, 359/530, 359/529, 356/437, 250/338.5
• US Class Current: 359/601
• CPC Class Codes: G02B 23/16 Housings; Caps; Mountings; Supports, e.g. with counterweight
• CPC Class Codes: G02B 27/0983 being curved
• CPC Class Codes: G02B 27/0994 Fibers, light pipes optical fibers per se G02B6/02
• CPC Class Codes: G02B 5/124 plural reflecting elements forming part of a unitary plate or sheet

Abstract

A telescope baffle system is disclosed for use with optical instruments. The baffle structure consists of highly reflective low scatter annular arrays of retro-reflecting cube corners which have the capability of returning rays back upon themselves such that most off-axis radiation striking one of the baffle annular arrays is reflected back to its source rather than being absorbed or scattered by the baffle.

Claims

1. A telescope baffle system for use with any optical instrument which processes light with both on-axis radiation and off-axis radiation, wherein said optical instrument has a chamber which conducts said light along an optical axis from an input side to optical elements on an output side, and wherein said telescope baffle system comprises a plurality of retro-reflector array elements which are mounted inside said chamber, said plurality of retro-reflector array elements having retro-reflective surfaces which face said input side of said chamber to eliminate off-axis radiation, said retro-reflector array elements each having an absorptive coating on their output side to absorb off-axis radiation so that it is not reflected back towards said optical instrument.

2. A telescope baffle system, as defined in claim 1, wherein each of said retro-reflector array elements comprises an annular retro-reflective collar which is fixed inside said chamber, said annular retro-reflective collar forming a ring which has a center corresponding with the optical axis of said light to permit on-axis radiation to be conducted on to said optical elements, said annular retro-reflective collar having a retro-reflective coating on its input side which faces said input side of said chamber which forms thereby one of said retro-reflective surfaces which eliminates said off-axis radiation.

3. A telescope baffle system, as defined in claim 2, wherein said annular retro-reflective collar has a pseudo phase conjugate mirror on its input side which faces the input side of said chamber, said pseudo phase conjugate mirror reflecting off-axis radiation back along its angle of incidence to prevent it from reaching the optical elements of said optical instrument.

4. A telescope baffle system, as defined in claim 3, wherein said annular retro-reflective collars have tilts and measurements of curvatures such that said annular retro-reflective collars have a concave surface on their input sides which face the input side of said chamber, and wherein said retro-reflective arrays have periods which are nonuniform and reduced as one progresses from the input side of the chamber towards the output side of the chamber.

5. A telescope baffle system, as defined in claim 3, wherein said annular retro-reflective collars have tilts and measurements of curvatures such that said annular retro-reflective collars have a concave surface on their input sides which face the input side of said chamber, and wherein said retro-reflective arrays collars have periods which are constant and reduced as one progresses from the input side of the chamber towards the output side of the chamber.

6. A telescope baffle system, as defined in claim 2, wherein said annular retro-reflective collars have tilts and measurements of curvatures such that said annular retro-reflective collars have a concave surface on their input sides which face the input side of said chamber, and wherein said curvatures and tilts are nonuniform and are reduced as one progresses from the input side of the chamber towards the output side of the chamber.

7. A telescope baffle system, as defined in claim 1, wherein each of said retro-reflector array elements comprises a semi-circular retro-reflective collar which is fixed inside said chamber, said semi-circular retro-reflective collar forming a semi-circle which has center corresponding with the optical axis of said light to permit on-axis radiation to be conducted on to said optical elements, said semi-circular retro-reflective collar having a reflective coating on its input side which faces said input side of said chamber which forms thereby one of said retro-reflective surfaces which eliminates said off-axis radiation.

8. A telescope baffle system, as defined in claim 7, wherein said semi-circular retro-reflective collars have tilts and curvatures such that said semi-circular retro-reflective collars have a concave surface on their input sides which face the input side of said chamber, and wherein said semi-circular retro-reflective collars have periods which are nonuniform and reduced as one progresses from the input side of the chamber towards the output side of the chamber.

9. A telescope baffle system, as defined in claim 7, wherein said semi-circular retro-reflective collars have tilts and curvatures such that said semi-circular retro-reflective collars have a concave surface on their input sides which face the input side of said chamber, and wherein said semi-circular retro-reflective collars have periods which are constant as one progresses from the input side of the chamber towards the output side of the chamber.

10. A telescope baffle system for use with any optical instrument which processes light with both on-axis radiation and off-axis radiation, wherein said optical instrument has a chamber which conducts said light along an optical axis from an input side to optical elements on an output side, and wherein said telescope baffle system comprises a plurality of retro-reflector array annuli which are fixed inside said chamber, said plurality of retro-reflector array annuli having retro-reflective surfaces which face said input side of said chamber to eliminate off-axis radiation.

11. A telescope baffle system, as defined in claim 10, wherein each of said retro-reflector array annuli comprises an annular retro-reflective collar which is fixed inside said chamber, said annular retro-reflective collar forming a ring which has a center corresponding with the optical axis of said light to permit on-axis radiation to be conducted onto said optical elements, said annular retro-reflective collar being a pseudo phase conjugate mirror on its input side which faces said input side of said chamber which forms thereby one of said retro-reflective surfaces which eliminates said off-axis radiation by reflecting off-axis radiation back along its angle of incidence.

12. A telescope baffle system, as defined in claim 11, wherein said annular retro-reflective collars have curvatures and tilts such that said annular retro-reflective collars have a concave surface on their input sides which face the input side of said chamber, and wherein said curvatures and tilts are nonuniform and reduced as one progresses from the input side of the chamber towards the output side of the chamber.

13. A telescope baffle system, as defined in claim 11, wherein each of said annular retro-reflective collars has an inner diameter which decreases as one progresses from the input side of the chamber towards the output side of the chamber.

14. A telescope baffle system, as defined in claim 13, wherein said annular retro-reflective collars have measurements of curvatures such that said annular retro-reflective collars have a concave surface on their sides which face the input side of said chamber, and wherein said curvatures are nonuniform and reduced as one progresses from the input side of the chamber towards the output side of the chamber.

15. A telescope baffle system, as defined in claim 10, wherein each of said retro-reflector array annuli comprises a semi-circular retro-reflective array collar which is fixed inside said chamber, said semi-circular retro-reflective collar forming a semi-circle which has a center corresponding with the optical axis of said light to permit on-axis radiation to be conducted on to said optical elements, said semi-circular retro-reflective collar having a reflective coating on its input side which faces said input side of said chamber which forms thereby one of said retro-reflective surfaces which eliminates said off-axis radiation.

16. A telescope baffle system, as defined in claim 15, wherein said semi-circular retro-reflective collars have curvatures such that said annular retro-reflective collars have a concave surface on their input sides which face the input side of said chamber, and wherein said curvatures are nonuniform and reduced as one progresses from the input side of the chamber towards the output side of the chamber.

17. A telescope baffle system, as defined in claim 16, wherein said semi-circular retro-reflective collars have varying curvatures with separation distances which are nonuniform.

18. A telescope baffle system, as defined in claim 16, wherein said semi-circular retro-reflective collars have varying curvatures with separation distances which are constant.

19. A telescope baffle system, as defined in claim 15, wherein said semi-circular retro-reflective collar has a black absorptive coating on its output side which faces the output side of said chamber, said black absorptive coating absorbing of-axis radiation to prevent it from reaching the optical elements of said optical instrument.

20. A telescope baffle system, as defined in claim 19, wherein said semi-circular retro-reflective collars have curvatures and separation distances which are nonuniform as required to optimize off-radiation rejection.