Patent ID: 7684048

Claim:
Apparatus for imaging a surface, comprising: an acousto-optic (AO) element having a radiation input surface and a radiation output surface, which is configured to receive a series of radio-frequency (RF) pulses and a radiation input at the radiation input surface and to generate in response thereto focused traveling beams from the radiation output surface; means for separating each of the traveling beams into one or more of (i) a plurality of phase-altered-traveling-beams or (ii) a plurality of orthogonal-polarized-traveling-beams; objective optics which are configured to focus the separated traveling beams onto the surface so as to form respective traveling spots thereon; collection optics, which are configured to (a) collect scattered radiation from the traveling spots, (b) perform one or more of (i) overlapping scattered radiation originating from one phase-altered-traveling-beam with scattered radiation originating from another phase-altered-traveling-beam or (ii) overlapping scattered radiation originating from one orthogonal-polarized-traveling-beam with scattered radiation originating from another orthogonal-polarized-traveling-beam and (c) to focus the scattered radiation to form respective image spots traveling along a line; a detector which is arranged to generate a signal in response to the respective image spots incident thereon; a detector entry port interposed between the collection optics and the detector, which is coincident with the line; and means for intercepting the scattered radiation and masking, from the detector, a portion of the scattered radiation collected by the collection optics.