Abstract: A telescope has an entrance pupil region; a first concave mirror (M1) belonging to a first rotationally symmetric aspheric surface and reflecting light passing through the entrance pupil region; a second convex mirror (M2) belonging to a second rotationally symmetric aspheric surface and reflecting light reflected by the first mirror; a third convex mirror (M3) belonging to a third rotationally symmetric aspheric surface and reflecting light reflected by the second mirror; a fourth concave mirror belonging to a fourth rotationally symmetric aspheric surface and reflecting light reflected by the second mirror to an exit pupil. The first, second, third and fourth rotationally symmetric aspheric surfaces are centered on the symmetry axis of the third mirror. The first, second and fourth mirrors are centered along the first direction perpendicular to the optical axis and off-centered in a second direction perpendicular to the symmetry axis and to the first direction.

Abstract: A real time SAR processing system for processing synthetic aperture radar (SAR) return signals and a method for real time processing of SAR return signals. The real time SAR processing system for processing synthetic aperture radar return signals comprises a light source (1) for generating a coherent, plane electromagnetic wave; light modulation means (2) for modulating the incident wave according to the radar return signals and outputting a modulated wave; and optical processing means (3) for submitting the modulated wave to an optical signal processing for radar image reconstruction. The light modulation means (2) comprises a plurality of addressable pixels (30) which are controlled based on the radar return signals. Light detection means (4) for detecting the processed wave and generating a corresponding electrical radar image signal are provided.

Abstract: A telescope has an entrance pupil region; a first concave mirror (M1) belonging to a first rotationally symmetric aspheric surface and reflecting light passing through the entrance pupil region; a second convex mirror (M2) belonging to a second rotationally symmetric aspheric surface and reflecting light reflected by the first mirror; a third convex mirror (M3) belonging to a third rotationally symmetric aspheric surface and reflecting light reflected by the second mirror; a fourth concave mirror belonging to a fourth rotationally symmetric aspheric surface and reflecting light reflected by the second mirror to an exit pupil. The first, second, third and fourth rotationally symmetric aspheric surfaces are centered on the symmetry axis of the third mirror. The first, second and fourth mirrors are centered along the first direction perpendicular to the optical axis and off-centered in a second direction perpendicular to the symmetry axis and to the first direction.

Abstract: This invention relates to a real time SAR processing system for processing synthetic aperture radar (SAR) return signals and a method for real time processing of SAR return signals. The real time SAR processing system for processing synthetic aperture radar return signals comprises a. light source (1) for generating a coherent, plane electromagnetic wave; light modulation means (2) for modulating the incident wave according to the radar return signals and outputting a modulated wave; and optical processing means (3) for submitting the modulated wave to an optical signal processing for radar image reconstruction. The light modulation means (2) comprises a plurality of addressable pixels (30) which are controlled based on the radar return signals. Light detection means (4) for detecting the processed wave and generating a corresponding electrical radar image signal are provided.

Abstract: A high resolution spectrometer with a large free spectral range comprising an entrance slit for a beam of electromagnetic radiation to be analyzed, a first dispersion device for dispersing the beam to be analyzed into various wavelength components in a first direction, a second dispersion device for dispersing each wavelength component output from the first dispersion device in a second direction, and an imaging device comprising a sensitive detection spectrum surface on which the beam dispersed in the first and second directions is focused, the first dispersion device being an optical filter that varies linearly and has a surface on which the beam to be analyzed is focused, each point on the surface of the filter operating like a pass band filter with a central frequency varying linearly in the first direction.

Abstract: A high resolution spectrometer with a large free spectral range comprising an entry slit for a beam of electromagnetic radiation to be analyzed, a first dispersion device for dispersing the beam to be analyzed into various wavelength components in a first direction, a second dispersion device for dispersing each wavelength component output from the first dispersion device in a second direction, and an imaging device comprising a sensitive detection spectrum. surface on which the beam dispersed in the first and second directions is focused, the first dispersion device being an optical filter that varies linearly and has a surface on which the beam to be analyzed is focused, each point on the surface of the filter operating like a pass band filter with a central frequency varying linearly in the first direction.