Konferans bildirisi Açık Erişim

High-precision measurements of reflectance, transmittance, and scattering at 632.8 nm

2012    Nasibov, Humbat; Mamedbeili, Izmir; Riza, Dadash; Balaban, Ertan; Hacizade, Fikret

Progresses in the optical coatings and optical material fields require an increase in the sensitivity and accuracy of the optical parameters' measurement methods and systems. In this work we describe a flexible and high-accuracy system for measuring the main optical characteristics at 632.8 nm wavelength. The system comprises two methods: a laser ratiometric measurement method for absolute measurement of the transmittance and the specular reflectance, and an integrating-sphere method for assessment of the total integrated scattering. The system utilizes an intensity stabilized He-Ne laser as a light source. Two four-element trap detectors are used: the first for monitoring of laser power, the second (fixed on a motorized stage) for the measurement of reflectance and transmittance, one after another. A PMT mounted to the exit port of a 40 cm diameter integrating hemisphere, is used for measuring the total integrated scattering. A series of measurements with several reference mirrors showed that the system is able to measure the specular reflectance with a reproducibility of <0.005%, transmittance of 0.005% with a reproducibility <0.005%, and total integrated scattering about 10 ppm, with a reproducibility of <5 ppm at 2 sigma. The system allows characterizing of optical components with diameters between 5 mm and 50 mm.