DUV scattering measurements as a tool for characterization of UV-optical surfaces |
| |
Authors: | O Apel K Mann |
| |
Institution: | Laser-Laboratorium-G?ttingen e.V., Hans-Adolf-Krebs-Weg 1, 37077 G?ttingen, Germany (Fax: +49-551/5035-99, E-mail: oapel@llg.gwdg.de), DE
|
| |
Abstract: | A sensitive total-scattering measurement setup for the DUV spectral range is presented, which allows precise determination
of both forward and backward scatter losses from optical components for excimer lasers with a sensitivity below 10 ppm for
248 nm and 50 ppm for 193 nm.
Scattering from several different coated and uncoated DUV optical surfaces was monitored. For uncoated samples, the backward
scatter losses are in good agreement with the predictions of scalar scattering theory, indicating that in this case scattering
is mainly determined by surface effects. Although forward and backward scatter losses are of the same order of magnitude for
uncoated samples, they differ by up to two orders of magnitude for high-reflection- and by one order of magnitude for anti-reflection-coated
samples. The experimental data demonstrate that the anti-reflection coatings suffer from substantial losses due to forward
scattering, whereas backward scattering is the predominant loss channel for high-reflection coatings. In addition, the strong
influence of defects and impurities on the total scattering is demonstrated.
Received: 5 June 2000 / Accepted: 6 June 2000 / Published online: 13 September 2000 |
| |
Keywords: | PACS: 78 35 +c 07 06 -j |
本文献已被 SpringerLink 等数据库收录! |
|