Patent ID: 11899371
Assignee: NIKON CORPORATION
Field: nan (nan)
Classification: CPC nan | IPC G

Claim 0:
1. An optical imaging system having an optical axis and operable to form an image of an object, the optical imaging system comprising:
a convex reflector unit situated on the optical axis and defining a first opening therein;
a concave reflector unit situated on the axis and defining a second opening therein; and
an illumination reflector element disposed on the optical axis between the convex reflector unit and the concave reflector unit,
the system configured to:
receive, at a surface of the convex reflector unit, optical radiation in a form of two diffracted beams of radiation produced by a substantially one-dimensional (1D) diffractive structure defined by the object, and delivered thereto through the second opening, and
form an image of the object by irradiating an image plane with the optical radiation after the optical radiation has been reflected from a surface of the concave reflector unit and after the optical radiation has passed through the first opening,
wherein the illumination reflector element is situated to reflect an illumination radiation to the object, the two diffracted beams of radiation generated at the object in response to the illumination radiation from the illumination reflective element, and the illumination reflective element is situated to block light propagating between the two diffracted beams of radiation from the object.