Abstract:
A method and apparatus for measuring nonreciprocal optical effects contemplates directing two circularly polarized optical beams having a known phase relation to each other at a sample, and detecting the difference in phase between the two beams after they have encountered the sample. In a transmission measurement the two circularly polarized beams have the same handedness, but pass through the sample in opposite directions. In a reflection measurement, the two circularly polarized beams have opposite handedness, but encounter the sample in the same direction. In a particular embodiment of the invention a linearly polarized beam is introduced into a Sagnac interferometer and split into two linearly polarized beams which are ultimately recombined.
Abstract:
A multi-aperture interferometric optical system collects light propagating from a source of light and develops overlapping diffraction patterns on an optical detector that produces output signals for processing to automatically focus the optical system and form an image corresponding to the diffraction patterns. A preferred embodiment of the invention is a large aperture orbiting, earth-watching ring interferometric optical system configured such that there is no macro-structure pointing. Four mirror-ring structures direct incoming light to a multi-spectral primary optical detector that acquires light-pattern information to focus the optical system and derive an image.
Abstract:
A multi-aperture interferometric optical system collects light propagating from a source of light and develops overlapping diffraction patterns on an optical detector that produces output signals for processing to form an image corresponding to the diffraction patterns. A preferred embodiment of the invention is a large aperture orbiting, earth-watching ring interferometric optical system configured such that there is no macro-structure pointing. Four mirror-ring structures direct incoming light to a multi-spectral primary optical detector that acquires light-pattern information from which an image can be derived.
Abstract:
A multi-aperture interferometric optical system collects light propagating from a source of light and develops overlapping diffraction patterns on an optical detector that produces output signals for processing to form an image corresponding to the diffraction patterns. A preferred embodiment of the invention is a large aperture orbiting, earth-watching ring interferometric optical system configured such that there is no macro-structure pointing. Four mirror-ring structures direct incoming light to a multi-spectral primary optical detector that acquires light-pattern information from which an image can be derived.
Abstract:
A multi-aperture interferometric optical system collects light propagating from a source of light and develops overlapping diffraction patterns on an optical detector that produces output signals for processing to automatically focus the optical system and form an image corresponding to the diffraction patterns. A preferred embodiment of the invention is a large aperture orbiting, earth-watching ring interferometric optical system configured such that there is no macro-structure pointing. Four mirror-ring structures direct incoming light to a multi-spectral primary optical detector that acquires light-pattern information to focus the optical system and derive an image.
Abstract:
A method and apparatus 10 for sensing and measuring the quality of the wavefront of a substantially collimated incoming optical beam 12. Incoming beam 12 is directed through a polarizer 14 and toward a polarizing beam splitter 14 where it is separated into an S-polarized beam 18 and a P-polarized beam 20. Beams 18,20 are directed in opposite directions along a common closed path of a modified cyclic interferometer 22. This closed path includes mirrors 24,26 and focusing means 28,30 for focusing the P- and S-polarized beams 18,20 at a common focal region on the path and for recollimating each beam 18,20 after it passes through the focal region. At the focal region is located a specially constructed polarizer component 32 with an optical aperture 34. The aperture 34 is centered on the centroid of the focused beams and is angularly oriented about an optical axis of the closed path so that it transmits substantially all of the beam traveling in one direction and is an effective optical spatial filter for the beam traveling in the opposite direction. After being recollimated and returned to beam splitter 16 the beams 18,20 are recombined in a common path 36 and oriented in a common plane of polarization by polarizer 38 thereby causing them to interfere. The resultant fringe field is read by reader 40 and analyzed by receiver electronics 42, control electronic means 44 and memory device means 46. The apparatus 10 can operate with either a continuous wave or a pulsed wave of incident optical radiation.
Abstract:
A multi-aperture interferometric optical system collects light propagating from a source of light and develops overlapping diffraction patterns on an optical detector that produces output signals for processing to form an image corresponding to the diffraction patterns. A preferred embodiment of the invention is a large aperture orbiting, earth-watching ring interferometric optical system configured such that there is no macro-structure pointing. Four mirror-ring structures direct incoming light to a multi-spectral primary optical detector that acquires light-pattern information from which an image can be derived.
Abstract:
A method and corresponding device, are provided for detecting the propagation time variations in the ring of an interferometer and includes phase modulation of the contrarotating waves travelling through the ring by means of assymetric square waves at a period twice the initial propagation time, which create level zero phase shift stretches in the modulation of the difference between the two waves emerging from the ring. These level stretches result in pulses in the detected output signal whose width is variable with the propagation time. The invention applies particularly to the control of the wave length of the source of the interferometer, particularly with respect to temperature variations of the source.
Abstract:
Le procédé, et le dispositif correspondant, de détection des variations de temps de propagation dans l'anneau d'une interféromètre utilise une modulation de phase des ondes contra-rotatives parcourant l'anneau par des créneaux asymétriques à une période double d'un temps de propagation initial, qui créent des paliers à décalage de phase nul dans la modulation de la différence des deux ondes émergent de l'anneau. Ces paliers se traduisent par des impulsions dans le signal détecté de sortie dont la largeur est variable avec le temps de propagation. L'invention s'applique, notamment au contrôle de la longueur d'onde de la source de l'interféromètre, particulièrement du fait des variations de température de la source.