Effects of a measurement floor on Mueller matrix measurements in a DRR BSDF system

摘要

Since the bidirectional scatter distribution function (BSDF) is proportional to the intensity of the scattered light, a BSDFsystem with the addition of a dual rotating retarder system can be used to calculate the Mueller matrix of a scatterer. Anadvantage of a BSDF system is the large dynamic range which allows the measurement of scattered light both near toand far from the specular region. In some cases as measurements move away from the specular and into the scatterregion, the measured signal decreases and the system reaches a measurement floor. Therefore, any BSDF and Muellermatrix measurements are dependent on the scatter from the sample and on the noise floor of the system. Since the noisefloor of an electro-optical system is near constant, the Mueller matrix measurement of the noise floor will be that of aperfect depolarizer. As the measurement space moves away from the high-signal region, the scattered signal decreasesand the floor of the system is approached so the Mueller matrix measurements can shift towards a perfect depolarizer.The rate and location of this shift will be dependent on how Lambertian the sample is and the ratio of signal to noise inthe system. Because of this tendency, caution must be taken when drawing conclusions about the Mueller matrix ofscattered light, particularly in the scatter measurement region where the measured signal approaches the system floor.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.