In this Letter, we present a novel design method of image-side telecentric freeform imaging systems. The freeform surfaces in the system can be generated using a point-by-point design approach starting from an initial...In this Letter, we present a novel design method of image-side telecentric freeform imaging systems. The freeform surfaces in the system can be generated using a point-by-point design approach starting from an initial system consisting of simple planes. The proposed method considers both the desired object–image relationships and the telecentricity at the image-side during the design process. The system generated by this method can be taken as a good starting point for further optimization. To demonstrate the benefit and feasibility of our method,we design two freeform off-axis three-mirror image-side telecentric imaging systems in the visible band. The systems operate at F/1.9 with a 30 mm entrance pupil diameter and 5° diagonal field-of-view. The modulation-transfer-function curves are above 0.69 at 100 lps/mm.展开更多
Nested multilayer mirrors are commonly used in X ray telescope structure to increase the collecting area. To balance the difficulty and cost of producing these mirrors, Wolter-I structures are replaced with conical Wo...Nested multilayer mirrors are commonly used in X ray telescope structure to increase the collecting area. To balance the difficulty and cost of producing these mirrors, Wolter-I structures are replaced with conical Wolter-I structures, but these can lead to significantly poorer angular resolutions. In this Letter, we consider changing one of the mirror shapes（paraboloid or hyperboloid） of a Wolter-I structure to a conical mirror shape, while the other mirror shape remains a quadric surface-type structure, which can thus ensure the imaging quality. The cone-hyperboloid structure is nested to obtain on-axis angular resolution and off-axis images.展开更多
文摘In this Letter, we present a novel design method of image-side telecentric freeform imaging systems. The freeform surfaces in the system can be generated using a point-by-point design approach starting from an initial system consisting of simple planes. The proposed method considers both the desired object–image relationships and the telecentricity at the image-side during the design process. The system generated by this method can be taken as a good starting point for further optimization. To demonstrate the benefit and feasibility of our method,we design two freeform off-axis three-mirror image-side telecentric imaging systems in the visible band. The systems operate at F/1.9 with a 30 mm entrance pupil diameter and 5° diagonal field-of-view. The modulation-transfer-function curves are above 0.69 at 100 lps/mm.
基金supported by the National Science Instrument and Equipment Development Major Project of Ministry of Science and Technology of China(Nos.2012YQ24026402 and 2012YQ04016403)the Youth Science Fund Project of the National Natural Science Fund of China(No.11505129)
文摘Nested multilayer mirrors are commonly used in X ray telescope structure to increase the collecting area. To balance the difficulty and cost of producing these mirrors, Wolter-I structures are replaced with conical Wolter-I structures, but these can lead to significantly poorer angular resolutions. In this Letter, we consider changing one of the mirror shapes（paraboloid or hyperboloid） of a Wolter-I structure to a conical mirror shape, while the other mirror shape remains a quadric surface-type structure, which can thus ensure the imaging quality. The cone-hyperboloid structure is nested to obtain on-axis angular resolution and off-axis images.
