摘要
Bragg gratings are straightforwardly written into a l O-ring photonic crystal fibre （PCF） with a highly Ge^3＋-doped core by means of a 193nm ArF excimer laser. The grating inscription efficiency is improved, due to enhanced photosensitivity and the large overlap between the fundamental mode and the photosensitive core. The exposure duration only lasts less than 180s. In addition, the high-index core changes the modai properties of the PCF and two groups of higher order mode resonance dips are therefore obtained. A strong cladding mode resonance is observed, because the LP02-1ike mode has a large overlap integral with the fundamental mode.
Bragg gratings are straightforwardly written into a l O-ring photonic crystal fibre （PCF） with a highly Ge^3＋-doped core by means of a 193nm ArF excimer laser. The grating inscription efficiency is improved, due to enhanced photosensitivity and the large overlap between the fundamental mode and the photosensitive core. The exposure duration only lasts less than 180s. In addition, the high-index core changes the modai properties of the PCF and two groups of higher order mode resonance dips are therefore obtained. A strong cladding mode resonance is observed, because the LP02-1ike mode has a large overlap integral with the fundamental mode.
基金
Supported by the National Key Basic Research Programme of China under Grant No 2003CB314906, the National High-Technology Research and Development Programme of China under Grant No 2006AA01Z217, the National Natural Science Foundation of China under Grant No 60736039, the Programme for New Century Excellent Talents in University （NCET-06-0271）, and Open Research Fund of Key Laboratory of Opto-Electronic Information Science and Technology （Ministry of Education） in Nankai University . The authors would like to thank the 46th Research Institute, MII, Tianjin, China for providing the photonic crystal fibres.
