Patent ID: 8598488

Claim:
An apparatus comprising: a first beam cropper having a first diaphragm defining a first aperture disposed in a beam transmission path along which a beam of radiation pulses is transmittable, the beam of radiation pulses radiation pulse having a first spot with a first spot size, wherein a first beam cropper is configured such that a portion of a radiation pulse in a beam of radiation pulses in the beam transmission path is selectively transmittable through the first aperture relative to the first diaphragm to pass an intermediate cropped radiation pulse having an intermediate cropped spot with an intermediate cropped spot size less than the first spot size; and a second beam cropper having a second diaphragm defining a plurality of second apertures, wherein the second beam cropper is configured such that each of the plurality of second apertures is selectively disposable in the beam transmission path, wherein each of the plurality of second apertures is configured such that a portion of the cropped radiation pulse is selectively transmittable through the plurality second apertures relative to the second diaphragm to pass a second cropped radiation pulse having a second cropped spot with a second cropped spot size less the intermediate cropped spot size.