摘要
RECENTLY, excimer laser devices, which have higher-energy density output in pulsed ultravio-let (UV) light (193 or 248 nm), have been employed to generate some thin film struc-tures. The principle of this technique, which is also called pulsed laser deposition (PLD)technique, is that the exposed material could be ablated out of the sample by the focusing laserbeam, and redeposit on a substrate to form thin-film structures under certain conditions. Onthe other hand, researchers have obtained high-quality Bragg gratings in photosensitive
