Patent ID: 8820948

Claim:
An aerial image sensor (AIS) system for use in a photolithographic imaging system, the AIS system comprising: a first component of the AIS system having a slit in a surface of said first component, and an axis that is perpendicular to said surface, said first component transmitting radiation incident thereon through the slit to form first radiation; and a light collector of the AIS system disposed behind said first component at a working distance defining a gap between said light collector and said first component, said light collector having an entrance region bound by an entrance edge, an exit region bound by an exit edge, and a reflecting surface connecting the entrance and exit edges, said reflecting surface being rotationally symmetric about said axis and disposed at a grazing angle with respect to said slit such that the entrance region receives the first radiation within a first range of angles, said reflecting surface reflecting radiation received by the entrance region towards the exit region, and said exit region emits said radiation within a second range of angles.