Abstract: A freeform surface off-axial three-mirror imaging system comprising a primary mirror, a secondary mirror, a tertiary mirror, and a detector. The secondary mirror comprises a first freeform surface and a second freeform surface. Each reflective surface of the primary mirror, the first freeform surface, the second freeform surface and the tertiary mirror is an xy polynomial freeform surface. The freeform surface off-axial three-mirror imaging system comprises a first field of view formed by the first freeform surface and a second field of view formed by the second freeform surface.

Abstract: A freeform surface off-axis three-mirror optical system comprises a primary mirror, a secondary mirror, a tertiary mirror, an aperture stop located on the secondary mirror, and an image surface. An incident light beam emitted from an object irradiates and is reflected on the primary mirror to form a first reflected light beam. The first reflected light beam irradiates and is reflected on the secondary mirror to form a second reflected light beam. The second reflected light beam passes through the incident light beam, and then irradiates and is reflected on the tertiary mirror to form a third reflected light beam. The third reflected light beam passes through the incident light beam and does not pass through the secondary mirror, and finally reaches the image surface for imaging. A reflective surface of each of the primary mirror, the secondary mirror, and the tertiary mirror is an xy polynomial freeform surface.

Abstract: A method for designing freeform surface imaging system comprises: constructing a series of coaxial spherical systems with different optical power (OP) distributions; tilting all optical elements of each coaxial spherical system by a series of angles to obtain a series of off-axis spherical systems; finding all unobscured off-axis spherical systems; and then specifying a system size or structural constraints, and finding a series of compact unobstructed off-axis spherical systems; constructing a series of freeform surface imaging systems based on the series of compact unobstructed off-axis spherical system, and correcting the OP of entire system; improving an image quality of each freeform surface imaging systems and finding an optimal tilt angle of an image surface; and automatically evaluating an image quality of each freeform surface imaging system based on an evaluation metric, and outputting the freeform surface imaging systems that meet a given requirements.

Abstract: A freeform surface off-axis three-mirror optical system comprises a primary mirror, a secondary mirror, a tertiary mirror, an aperture stop located on the secondary mirror, and an image surface. An incident light beam emitted from an object irradiates and is reflected on the primary mirror to form a first reflected light beam. The first reflected light beam irradiates and is reflected on the secondary mirror to form a second reflected light beam. The second reflected light beam passes through the incident light beam, and then irradiates and is reflected on the tertiary mirror to form a third reflected light beam. The third reflected light beam passes through the incident light beam and does not pass through the secondary mirror, and finally reaches the image surface for imaging. A reflective surface of each of the primary mirror, the secondary mirror, and the tertiary mirror is an xy polynomial freeform surface.

Abstract: A freeform surface off-axial three-mirror imaging system comprising a primary mirror, a secondary mirror, a tertiary mirror, and a detector. The secondary mirror comprises a first freeform surface and a second freeform surface. Each reflective surface of the primary mirror, the first freeform surface, the second freeform surface and the tertiary mirror is an xy polynomial freeform surface. The freeform surface off-axial three-mirror imaging system comprises a first effective focal length and a second effective focal length different from the first effective focal length.

Abstract: A freeform surface off-axial three-mirror imaging system is provided. The freeform surface off-axial three-mirror imaging system comprises a primary mirror, a secondary mirror, and a compensating mirror. The primary mirror, the secondary mirror, and the compensating mirror are located adjacent and spaced away from each other. A surface shape of each of the primary mirror and the secondary mirror is a quadric surface. The primary mirror is used as an aperture stop. A surface shape of the compensating mirror is a freeform surface. A light emitted from a light source is reflected by the primary mirror, the secondary mirror, and the compensating mirror to form an image on an image plane.

Abstract: A freeform surface optical telescope imaging system is provided. The freeform surface optical telescope imaging system comprises a primary mirror, a secondary mirror, a compensating minor, and a spherical mirror. The primary minor, the secondary minor, the compensating minor, and the spherical mirror are spaced from each other. A surface shape of each of the primary mirror and the secondary mirror is a quadric surface. The primary mirror is used as an aperture stop. A surface shape of the compensating mirror is a freeform surface. A surface shape of the spherical mirror is a spherical surface. A light emitted from a light source would be reflected by the primary mirror, the secondary minor, the compensating mirror, and the spherical mirror to form an image on an image plane.

Abstract: A freeform surface off-axial three-mirror imaging system comprising a primary mirror, a secondary mirror, a tertiary mirror, and an image sensor. Each reflective surface of the primary mirror, the secondary mirror, and the tertiary mirror is an xy polynomial freeform surface. A field angle of the freeform surface off-axial three-mirror imaging system is larger than or equal to 60°×1°. An F-number of the freeform surface off-axial three-mirror imaging system is less than or equal to 2.5.

Abstract: The present invention relates to a method for designing a freeform surface reflective imaging system, comprising: selecting an initial system, wherein an FOV of the initial system is X0×Y0; selecting an FOV sequence as [X0, Y0], [X1, Y1], [X2, Y2], . . . , [Xn, Yn], while the FOV of the system to be designed is Xn×Yn, and X0<X1<X2< . . . <Xn, Y0<Y1<Y2< . . . <Yn; using point-by-point methods to construct all freeform surfaces of the initial system in the FOV of X1×Y1; setting the system obtained in the last step as a second initial system for system construction in the FOV of X2×Y2; repeating the last step to execute system construction in the order of the FOV sequence until the final FOV Xn×Yn is obtained.

Abstract: The present disclosure relates to a method of designing a freeform surface off-axial imaging system. The method comprises the steps of establishing an initial system and selecting feature fields; gradually enlarging a construction of feature field, and constructing the initial system into a freeform surface system; and expanding a construction area of each freeform surface of the freeform surface system, and reconstructing the freeform surface in an extended construction area.

Abstract: A freeform surface imaging spectrometer system including a primary mirror, a secondary mirror, a tertiary mirror, and a detector is provided. The secondary mirror is a grating having a freeform surface shape, and the grating having the freeform surface shape is obtained by intersecting a set of equally spaced parallel planes with a freeform surface. A plurality of feature rays exiting from a light source is successively reflected by the primary mirror, the secondary mirror and the tertiary mirror to form an image on an image sensor. A reflective surface of each of the primary mirror, the tertiary mirror surface and the tertiary mirror is an xy polynomial freeform surface.

Abstract: The present invention relates to a freeform surface reflective infrared imaging system comprising a primary mirror, a secondary mirror, a tertiary mirror, and an infrared light detector. Each reflective surface of the primary mirror, the secondary mirror, and the tertiary mirror is an xy polynomial freeform surface. A field of view of the freeform surface reflective infrared imaging system is larger than or equal to 40°×30°. An F-number of the freeform surface reflective infrared imaging system is less than or equal to 1.39.

Abstract: The present invention relates to a method for designing a freeform surface reflective imaging system, comprising: selecting an initial system, wherein an FOV of the initial system is X0×Y0; selecting an FOV sequence as [X0, Y0], [X1, Y1], [X2, Y2], . . . , [Xn, Yn], while the FOV of the system to be designed is Xn×Yn, and X0<X1<X2< . . . <Xn, Y0<Y1<Y2< . . . <Yn; using point-by-point methods to construct all freeform surfaces of the initial system in the FOV of X1×Y1; setting the system obtained in the last step as a second initial system for system construction in the FOV of X2×Y2; repeating the last step to execute system construction in the order of the FOV sequence until the final FOV Xn×Yn is obtained.

Abstract: A method for designing illumination system with freeform surface, the method comprising: presupposing a plurality of expected light spots; establishing an initial system, wherein the initial system comprises a plurality of collimated light sources, a plane lens and a target plane; designing a sphere lens to replace the plane lens, and obtaining a before-construction-iteration illumination system; selecting a plurality of feature rays and obtaining a plurality of target points; taking the before-construction-iteration illumination system as an initial construction-iteration system, and obtaining an after-construction-iteration illumination system with freeform surface by making multiple construction-iteration, wherein the illumination system with freeform surface is configured to form the plurality of expected light spots.

Abstract: A freeform surface off-axial three-mirror imaging system comprising a primary mirror, a secondary mirror, a tertiary mirror, and a detector. The secondary mirror comprises a first freeform surface and a second freeform surface. Each reflective surface of the primary mirror, the first freeform surface, the second freeform surface and the tertiary mirror is an xy polynomial freeform surface. The freeform surface off-axial three-mirror imaging system comprises a first effective focal length and a second effective focal length different from the first effective focal length.

Abstract: A freeform surface off-axial three-mirror imaging system comprising a primary mirror, a secondary mirror, a tertiary mirror, and a detector. The secondary mirror comprises a first freeform surface and a second freeform surface. Each reflective surface of the primary mirror, the first freeform surface, the second freeform surface and the tertiary mirror is an xy polynomial freeform surface. The freeform surface off-axial three-mirror imaging system comprises a first field of view formed by the first freeform surface and a second field of view formed by the second freeform surface.

Abstract: A freeform surface off-axial three-mirror imaging system comprising a primary mirror, a secondary mirror, a tertiary mirror, and a detector. The secondary mirror defines a first location and a second location. Each reflective surface of the primary mirror, the secondary mirror and the tertiary mirror is an xy polynomial freeform surface. A working distance of the freeform surface off-axial three-mirror imaging system is greater than 125 mm.

Abstract: A method of designing an freeform surface off-axial three-mirror imaging system is provided. The method includes: establishing an initial system and T (T?2) object-image relationships according to a design goal, and selecting M feature fields for each object-image relationship; using feature rays of the T object-image relationships to construct a freeform surface system by using the initial system; step (S3), the freeform surface system obtained in step (S2) is used as another initial system, using iterative process to reduce a deviation between actual intersection points and ideal target points of the feature rays and feature surfaces, iteratively reconstructing free-form surfaces in the free-form surface system.

Abstract: A point-by-point design method for off-axis aspheric optical system, in which feature light rays from different field angles and aperture coordinates are considered. Some of the feature data points are calculated first and surface fitted into an initial aspheric surface. Then, intermediate point calculations, feature data point calculations, and aspheric surface fitting were repeated continuously to calculate remaining feature data points and the desired aspheric surface are repeated continuously to calculate remaining feature data points and a desired aspheric surface. A least-squares method with a local search algorithm is used for aspheric surface fitting and deviations in both the coordinates and normals are used to reduce error.

Abstract: An off-axis hybrid surface three-mirror optical system comprises a primary mirror, a secondary mirror, a tertiary mirror, and an image sensor. A reflective surface of the primary mirror is a sixth-order polynomial freeform surface of xy. A reflective surface of the secondary mirror is a sixth-order polynomial aspheric surface of xy. A reflective surface of the a tertiary mirror is a spherical surface of xy.