Patent ID: 6987568
Filing Date: 2006-01-17
Classification: G01N

Abstract:
1. An apparatus for measuring, as a function of incident beam geometry, the energy distribution emitted from a sample comprising: a) a source for producing a substantially collimated source radiation beam directed along an optical path; b) a paraboloidal reflector, having an optical axis disposed substantially parallel to the tangent of the sample surface at a selected sample location to be measured, the reflector positioned to intercept the collimated radiation beam at a first location on the reflector and to focus the intercepted beam to form an incident beam that strikes the sample at the selected sample location with a selected angle of incidence, whereupon the radiation from the incident beam is redirected by the sample into an emitted radiation distribution at least a portion of which is intercepted and reflected by the reflector; c) a detector for receiving the emitted radiation distribution reflected by the reflector; and d) a controller for varying the relative orientation of the source to the mirror to vary the angle of incidence of illumination, and for calculating the distribution of radiation received by the detector as a function of angle of emission from the sample and as a function of the angle of incidence of the illumination of the sample to compute a BRDF of the sample.