The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 22, 1994
Filed:
Mar. 25, 1992
Edward T Siebert, New Fairfield, CT (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
This invention provides embodiments of etalons (10, 14, 18, 22) that eliminate or minimize a falloff of relative radiation modulation as a function of wavelength or FOV. A first embodiment employs a dispersive coating, such as a rugate (12a, 12b, 16), to correct for the phase shift across an etalon step. A second embodiment employs a dispersive coating, such as a rugate (20a, 20b, 24), that provides a stepless etalon in which the phase shifts are generated by the coating. It is shown that in a rugate the phase shift on reflection is directly related to the phase of a sinusoidal index of refraction profile within the rugate, while the frequency of the sinusoidal index of refraction profile determines the wavelength at which the phase shift occurs. By changing the phase of the sinusoidal index of refraction variation as the period of the sinusoidal index of refraction variation is changed, a phase shift of incident radiation is produced that is a function of the wavelength of the incident radiation.