Patent ID: 7496120

Claim:
An optical monitoring system comprising: a beam input that defines an input beam segment of a beam path along a first axis; a reflection-inducing structure positioned along said input beam segment having a non-transmissive, reflective surface intercepting the first axis to reflect a light beam from said input beam segment to a reflected beam segment of said beam path along a second axis; a diffraction-inducing structure positioned along said reflected beam segment and intercepting said second axis to redirect a minor portion of said light beam along a third axis back toward said non-transmissive, reflective surface of said reflection-inducing structure to define a diffracted beam portion reflected from the surface, said diffraction-inducing structure being configured to enable a major portion of said light beam to pass to an output beam segment of said beam path along said second axis, thereby defining an output portion and a diffracted beam portion of said light beam; and a detector positioned relative to said reflection-inducing structure to generate a signal indicative of an optical property of said diffracted beam portion.