Patent ID: 6191863
Filing Date: 2001-02-20
Classification: G01J

Abstract:
A device for extinguishing a source comprising:means (1) for receiving an incident light beam (10) emanating from a punctual central source,a beam splitter (4, 58) receiving the incident beam (10) from the receiving means (1) and separating the said beam (10) into two secondary beams (13, 14) having the same optical power,two arms (5, 6, 75, 76) each provided with an optical system and traversed respectively by the secondary beams (13, 14), whereas the arms (5, 6, 75, 76) have optical paths of the same length and whereas the optical systems have opposite enlargements causing pupil turn-up in one of both arms (76) with respect to the pupil of the other arm (75), andmeans (7, 58) to combine secondary beams (5, 6, 75, 76) into an output beam (12), so that the contribution of the punctual source is cancelled in the output beam (12),characterised in that the said optical systems having focuses (F1, F2, F'1, F'2, C'1, C'2, S'1, S'2), principal planes (31, 32, 103, 104) and antiprincipal planes (33, 34, 105, 106), each of the focuses, principal planes and antiprincipal planes of one of the two optical systems is respectively superimposed on a focus, an antiprincipal plane and a principal plane of the other optical system after formation of the output beam (12) and the arms (5, 6, 75, 76) each having a number of passages through at least one of the focuses of the optical system corresponding to the said arm, the number of passages differs by an odd number.