Coma-compensation telescope

• US 4,624,538 A
• Filed: 05/28/1985
• Issued: 11/25/1986
• Est. Priority Date: 05/28/1985
• Status: Expired due to Term

• Current Assignee: Hughes Danbury Optical Systems Incorporated (Rtx Corporation)
• Original Assignee: The Perkin-Elmer Corporation (Thermo Fisher Scientific Incorporated)
• Inventors: MacFarlane, Malcolm J.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/737,762
• Time in Patent Office: 546 Days
• Field of Search: 350/620, 350/505, 350/1.1, 350/1.2, 350/1.4, 350/537, 350/612, 350/618, 350/619
• US Class Current: 250/330
• CPC Class Codes: G02B 17/0621 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 Class Codes: G02B 27/0068 having means for controlling the degree of correction, e.g. using phase modulators, movable elements controlling the phase of light using moving or deformable elements G02B26/06

Abstract

A telescope for eliminating on axis coma due to tilt of the secondary mirror in infrared astronomy. The secondary mirror of a reflecting telescope is formed to cause field coma to always be equal and opposite at the optical axis of the telescope to tilt coma regardless of the angle through the secondary mirror is tilted with respect to the optical axis.

Claims

1. In a two mirror telescope for use in infrared astronomy;

a primary mirror;

a secondary mirror disposed relative to said primary mirror to form a telescope;

means for tilting one of said mirrors continuously back and forth relative to the mechanical axis of the telescope;

said one of said mirrors being so constructed and arranged to have an intrinsic field coma on axis equal and opposite to tilt coma on axis at any tilt angle of said one mirror relative to said other mirror;

an infrared detector disposed on the mechanical axis at the back focus point of the telescope.

2. A telescope according to claim 1 wherein said one of said mirrors is said secondary mirror.

3. A telescope according to claim 1 wherein said primary mirror is formed to eliminate on axis spherical aberration regardless of the tilt of said primary mirror.

4. A telescope according to claim 3 wherein the conic constant K_s of said secondary mirror equals ##EQU9## where m=magnification of said secondary mirror,

F=system focal ratio

F_p =primary mirror focal ratio

E=vertex back focus divided by D_p

D_p =diameter of the entrance pupil.

5. A telescope according to claim 4 wherein the conic constant K_p of said primary mirror equals ##EQU10##