Development of an automated absorption measurement instrument (a “turn-key” system) for optical thin film coatings

Abstract

In this paper, we present the progress in the development of an automated measurement instrument for optical thin film coatings. Based on the laser-induced surface thermal lensing effect, the instrument shows a measurement sensitivity of absorbance down to 10 ppb, and it provides user-friendly operation of the whole absorption measurement process. Compared with a typical bench-top system the instrument requires little special skills from the operators and is therefore more reliable and reproducible. The specific applications of this instrument include measuring weak absorption, detecting local absorption defects, and monitoring laser-coating-interaction dynamics. The measurement results show that such a high sensitive automated instrument is an effective diagnostic tool for the optimization of optical thin film coatings with desired optical properties.