Abstract

Long period fiber gratings (LPFGs) with different transmission performance are fabricated with infrared ultra-short laser pulse direct writing of standard single mode fibers (SMF). Choosing proper parameters of laser inscription, the LPFG with a rejection band centered on 1310 nm and the depth of rejection band over 16 dB is routinely achieved. The length of such a LPFG is approximately 5 mm, including only 10 grating periods. Under similar writing conditions, increase of the total number of grating periods leads to the LPFG with transmission spectra of multi-resonance peaks. For the LPFG of a grating length of 17 mm (the number of scanning cycles now becomes 34 for 500 μm pitch), the resonant transmission loss around 1550 nm is over 11 dB.

© 2012 Optical Society of America