Anisotropic transformation of the beam quality of DPSS lasers for shaping of a narrow line focus for laser crystallization of Si

Autor: Wyacheslaw Grimm, Yuri V. Miklyaev, Andreas Hildebrandt, Vitalij Lissotschenko, Mikhail Ivanenko, Klaus Bagschik, Alexei Mikhailov
Rok vydání: 2008
Předmět:
Zdroj: SPIE Proceedings.
ISSN: 0277-786X
DOI: 10.1117/12.762091
Popis: Advanced laser crystallization of Si for flat panel displays demands a narrow line-shaped light focus with an ultimately high homogeneity. Key element of LIMO line shaping system is an anisotropic quality transformation of a multimode laser beam, which permits a very good homogenization for the long axis and tight focusing with a large depth of focus for the perpendicular high-quality axis. A prototype system has been built with a 90-W 532-nm DPSS laser. It provides a 59-mm long and down to 8 μm (FWHM) narrow focus with a residual inhomogeneity of only 1% (rms). The focus width is adjustable and its shape can be tuned from a quasi-Gauss to a top-hat intensity distribution. The depth of focus at 90% of the peak intensity DOF 0.9I varies from 120 μm for a line width of 8 μm to 275 μm for FWHM = 14 μm. The design of longer lines is in progress at LIMO.
Databáze: OpenAIRE