An image acquisition method includes defining a first optical sensor configuration of a matrix to acquire the image of a first celestial body of first nature, the first configuration having a plurality of unit pixels, defining at least one second optical sensor configuration of the matrix to acquire the image of the second celestial body of second nature, the second configuration having a plurality of macro-pixels formed by groupings of unit pixels, and selecting one of the optical sensor configurations, the selection being made according to the nature of the observed celestial body.

A polychromator system comprising: an optical element defining an aperture; a collimation mirror for receiving light via the aperture and reflecting substantially collimated light; at least a first dispersive optical component and a second dispersive optical component, each configured to disperse the substantially collimated light received from the collimation mirror by different amounts for different wavelengths and to provide cross-dispersed light having different wavelengths of light spaced along a first and second axis; and a focus mirror positioned to focus the cross-dispersed light onto a 2-D array detector to provide a plurality of aperture images of the aperture at a respective plurality of regions of the detector, each of the plurality of aperture images associated with a respective wavelength of the cross-dispersed light. Either one or both of the collimation mirror and the focus mirror is a freeform mirror having a reflective surface configured to mitigate effects of optical aberrations of the polychromator system over a plurality of the wavelengths of the cross-dispersed light along the first axis and the second axis and thereby optimise the resolution of the plurality of aperture images associated with the plurality of the wavelengths along the first axis and the second axis.

An all-reflective or reflective and cata-dioptric optical system includes a concave primary mirror having a central aperture and a radius, the primary mirror having one of a parabolic, non-parabolic conical, or aspherical surface, a convex secondary mirror facing the primary mirror, the secondary mirror having an aspherical surface, where an optical axis extends from a vertex of the primary mirror to a vertex of the secondary mirror, a concave tertiary mirror arranged behind the primary mirror, the tertiary mirror having one of a parabolic, non-parabolic conical or aspherical surface, a concave quaternary mirror arranged in the central aperture of the primary mirror or behind the primary mirror, the quaternary mirror having one of a spherical, parabolic, non-parabolic conical or aspherical surface, and/or at least one image plane having one or more aggregated sensors. Additional multispectral imaging may utilize beam splitter(s), folding mirror(s), focal length optimizer(s) and/or additional image planes.

A head-mounted fixing device includes: a head frame including two side frame portions, and a front frame portion located between the two side frame portions and connected to the two side frame portions, and the two side frame portions and the front frame portion being made of rigid materials; an elastic piece including one end connected to the front frame portion; a headgear including an arc portion and a top portion, wherein two ends of the arc portion are respectively connected to the two side frame portions, one end of the top portion is connected to another end of the elastic piece, and another end of the top portion is connected to the arc portion; it is characterized in that the front frame portion is used to abut against a user's forehead to provide a fulcrum.

The present application relates to a nonsymmetric freeform surface optical system including a primary reflecting mirror, a secondary reflecting mirror, and a tertiary reflecting mirror. A light beam from an object is reflected on the primary reflecting mirror to form a first reflected light beam, the first reflected light beam irradiates the secondary reflecting mirror and is reflected to form a second reflected light beam, the second reflected light beam irradiates the third reflecting mirror and is reflected to form a third reflected light beam, and the third reflected light beam reaches an image surface to form an image. The nonsymmetric freeform surface optical system has no rotational symmetry and no meridional symmetry.

The present application relates to a nonsymmetric freeform surface optical system including a primary reflecting mirror, a secondary reflecting mirror, and a tertiary reflecting mirror. A light beam from an object is reflected on the primary reflecting mirror to form a first reflected light beam, the first reflected light beam irradiates the secondary reflecting mirror and is reflected to form a second reflected light beam, the second reflected light beam irradiates the third reflecting mirror and is reflected to form a third reflected light beam, and the third reflected light beam reaches an image surface to form an image. The nonsymmetric freeform surface optical system has no rotational symmetry and no meridional symmetry.

Apparatuses and systems for a die-integrated aspheric mirror are described herein. One apparatus includes an ion trap die including a number of ion locations and an aspheric mirror integrated with the ion trap die.

An on-axis four mirror anastigmat telescope includes an entrance pupil configured to receive light from an image, and a mirror assembly. The mirror assembly has a first reflective surface having a central aperture formed therein, a second reflective surface, a third reflective surface having a central aperture formed therein, a fourth reflective surface, and an aperture stop. The mirror assembly is configured to receive light from the image on a common axis and to reflect the light successively by the four coaxial reflective surfaces through the aperture stop. The telescope further comprises a detector configured to receive light from the mirror assembly. The central aperture formed in the first reflective surface defines a field stop to limit the field of view.

A catheter system for optical coherence tomography includes an elongate catheter body, an optical fiber in the elongate catheter body, and an anamorphic lens assembly coupled with a distal end of the optical fiber. The optical fiber and the lens assembly are together configured to provide a common path for optical radiation reflected from a target and from a reference interface between the distal end of the optical fiber and the lens assembly.

A catheter system for optical coherence tomography includes an elongate catheter body, an optical fiber in the elongate catheter body, and an anamorphic lens assembly coupled with a distal end of the optical fiber. The optical fiber and the lens assembly are together configured to provide a common path for optical radiation reflected from a target and from a reference interface between the distal end of the optical fiber and the lens assembly.