Abstract: The invention provides a curved-slit imaging spectrometer, wherein a fiber bundle transfers a straight line image of a front objective lens to a curved slit, and the front objective lens doesn't need to have a curved image plane to directly abut the spectrometer, so that the system is less complicated, and the front objective lens and spectrometer have a simple structure. The arc-shaped or approximately arc-shaped curved slit matches the optimum imaging circle of the Offner-type spectrometer, thereby achieving an extra-long slit. The arced slit is 5 to 10 times longer than the straight slit of the classical Offner-type spectrometer. In the case of a compact size, the length of the slit can be greater than 100 mm. Also, the same spectral response function applies in different fields of view while presenting desirable imaging quality.

Abstract: The invention provides a wide-aperture spherical primary mirror off-axis afocal optical system, including a primary mirror, a secondary mirror and an aberration compensation mirror group. The primary mirror is a spherical reflector, the secondary mirror are higher-order aspherical reflectors. The primary mirror and the secondary mirror form an off-axis two-mirror system to compress the beam aperture. The aberration compensation mirror group is a coaxial reflective system that is used off-axis. The aberration compensation mirror group has focal power to produce compensation aberrations. The incident beam passes through and is reflected by the primary mirror and secondary mirror sequentially and enters the aberration compensation mirror group thereafter.

Abstract: The invention provides a curved-slit imaging spectrometer, wherein a fiber bundle transfers a straight line image of a front objective lens to a curved slit, and the front objective lens doesn't need to have a curved image plane to directly abut the spectrometer, so that the system is less complicated, and the front objective lens and spectrometer have a simple structure. The arc-shaped or approximately arc-shaped curved slit matches the optimum imaging circle of the Offner-type spectrometer, thereby achieving an extra-long slit. The arced slit is 5 to 10 times longer than the straight slit of the classical Offner-type spectrometer. In the case of a compact size, the length of the slit can be greater than 100 mm. Also, the same spectral response function applies in different fields of view while presenting desirable imaging quality.

Abstract: The invention provides a wide-aperture spherical primary mirror off-axis afocal optical system, including a primary mirror, a secondary mirror and an aberration compensation mirror group. The primary mirror is a spherical reflector, the secondary mirror are higher-order aspherical reflectors. The primary mirror and the secondary mirror form an off-axis two-mirror system to compress the beam aperture. The aberration compensation mirror group is a coaxial reflective system that is used off-axis. The aberration compensation mirror group has focal power to produce compensation aberrations. The incident beam passes through and is reflected by the primary mirror and secondary mirror sequentially and enters the aberration compensation mirror group thereafter.