Patent ID: 7488930

Claim:
A system for determining a characteristic of a sample, the system comprising: a light source for providing a light; a splitter receptive to said light from said light source to produce a sensing light portion and a reference light portion, said splitter having an asymmetrical ratio such that said sensing light portion is greater than said reference light portion; a sensing light path comprising, a light path configured to communicate said sensing light portion from said splitter and said sensing light portion reflected from the sample, a plurality of probe light paths configured to direct said sensing light portion at the sample and to receive said sensing light portion reflected from the sample, and an optical switch selectable to define communication between said light path and a selected at least one of said probe light paths; a reflecting device; a reference light path configured to communicate said reference light portion from said splitter, said reference light path further configured to direct said reference light portion at said reflecting device and to receive said reference light portion reflected from said reflecting device; means for generating an interference condition between said sensing light portion reflected from the sample and said reference light portion reflected from said reflecting device; a detector receptive to said sensing light portion reflected from the sample and said reference light portion reflected from said reflecting device, said detector generating a signal indicative of an interference of said sensing light portion reflected from the sample and said reference light portion reflected from said reflecting device; and processing means configured to determine a characteristic of the sample from said signal indicative of said interference of said sensing light portion reflected from the sample and said reference light portion reflected from said reflecting device.