Patent Number: 6,310,347

Title: Spectrometer with planar reflective slit to minimize thermal background at focal plane

Abstract: An optical spectrometer system has a central axis, a detector having a detector surface disposed at one end of the system and located at a focal plane of the optical spectrometer system. A cold stop is associated with the detector for permitting entrance of target source radiation onto the detector surface while blocking background radiation from surroundings. A cooling device is coupled to the detector for cooling it and the cold stop to a predetermined low temperature. A flat plate is provided and has an spectrometer slit formed in it, the plate having a flat surface facing the detector, the flat surface being coated with a highly reflective, low emissivity material. Fore-optic focusing lenses or mirrors are located in front of the flat plate for focusing radiation onto the slit on the flat plate between the fore-optic focusing and the collimating lenses. The collimating lenses between the flat plate and the cold stop collimate the light from the slit and form a pupil at the cold stop. Both the fore-optic focusing lenses and the collimating lenses are designed such that the space between them is telecentric. This allows the use of an uncooled flat high reflective slit body that has very little self emission yet it does not reflect the background thermal radiation from the spectrometer cavity into the cold stop and impinge on the detector.

Inventors: Shu; Ker-Li (Danbury, CT), Silverglate; Peter R. (Monroe, CT)

Assignee: Goodrich Corporation

International Classification: G01J 3/02 (20060101); G01J 5/06 (20060101); G01J 3/00 (20060101); G01J 005/02 ()

Expiration Date: 10/30/2018