Patent ID: 6950182
Filing Date: 2005-09-27
Classification: G01N

Abstract:
1. A system comprising a functional equivalent to a spatial filter which serves to attenuate an outer annular region from said electromagnetic beam as it passes therethrough; said functional equivalent to a spatial filter being present in the context of a system comprising: said functional equivalent to a spatial filter comprising an aperture prior to said sample system, and after the sample system a converging lens and a light fiber, said converging lens serving to image said aperture onto the input of said light fiber; such that in use the central portion of the electromagnetic beam which is caused to pass through said aperture, becomes focused on the input to said optical fiber by said converging lens after interaction with said sample system, and said optical fiber conveys said central portion of the electromagnetic beam to said means for detecting said electromagnetic beam after it interacts with said sample system; wherein said system is distinguished in that said converging lens is characterized by a selection from the group consisting of: and another of said at least two sequentially oriented elements in said input lens is made of fused silica; and b) said converging lens comprises a selection from the group consisting of: