METHOD AND SYSTEM FOR USE IN INSPECTION OF SAMPLES BY DETECTION OF OPTICALLY EXCITED EMISSION FROM THE SAMPLE

摘要

An optical method and system is presented for use in inspection of a sample by detecting stimulated / optically excited emission from the sample, for example by fluorescence. The optical system comprises a lens arrangement and a spatial filter. The lens arrangement defines an illumination path for directing illuminating light of a first wavelength range onto an illumination region on a sample plane and a collection path for directing reflected illuminating light of the first wavelength range and emitted light of a second wavelength range propagating from the sample plane towards a detection plane. The lens arrangement comprises a plurality of lenses configured for focusing the reflected illumination light onto a conjugate aperture plane and imaging the illumination region by the collected emitted light onto a conjugate sample plane corresponding to the detection plane, thereby spatially separating optical paths of the collected reflected illumination and emitted light portion in the vicinity of a focal location of the reflected light. The spatial filter may define a light blocking region in the collection path in the conjugate aperture plane at a focal location of the reflected illumination light, thereby substantially preventing the illuminating light from reaching the detection plane.