[15p-C42-1~11] 3.2 Equipment optics and materials

[15p-C42-6] Development of a Gonio-STAR GEM Scatterometer for Measuring the BRDF Ⅶ

〇Etsuo Kawate^1,2 (1.TRAS Inc., 2.AIST)

Keywords:ellipsoidal mirror, bidirectional reflectance distribution function, reflected light distribution

An ideal measurement apparatus of reflected light distribution introduces ellipsoidal mirrors. Nevertheless all attempts to develop it have been unsuccessful and so far there is no system like it. One cause of the failure is that the light emitted from near focus diffuses at the next focus. Our company has solved this problem by using two ellipsoidal mirrors alternately combined. The new apparatus is called ‘STAR GEM’. It can measure a reflected light distribution and an emitted light distribution from a sample. We present how to obtain the bidirectional reflectance distribution function (BRDF) from the measured distribution.