Patent ID: 8508748
Filing Date: 2013-08-13
Classification: G01B,G01N

Abstract:
1. An inspection system, comprising: an optical metrology tool having an optical column with a beam splitter optically coupled to an objective; illumination optics coupled to the beam splitter; an optical coherence tomography (OCT) focusing system having a broadband light source, a shiftable reflector, a photo-detector, all of which are connected by optical fiber to a fiber coupler in an interferometer configuration that is remote from the optical column, the OCT focusing system further including a fiber collimator optically coupled to the fiber coupler by an optical fiber, wherein the objective is optically coupled to the fiber coupler in the OCT focusing system by an optical fiber; and an illumination beam splitter optically coupled between the illumination optics and the beam splitter in the optical column, wherein the beam splitter is optically coupled to the fiber collimator, wherein the broadband light source is optically coupled to the illumination optics by a separate optical path that does not include the fiber coupler.