Title :
Asymmetrically Corrugated Long-Period Gratings by Burning Fiber Coating and Etching Cladding
Author :
Zhiquan Cui ; Weigang Zhang ; Fang Liu ; Hao Zhang ; Zhiyong Bai ; Pengcheng Geng ; Shecheng Gao
Author_Institution :
Key Lab. of Opt. Inf. Sci. & Technol., Nankai Univ., Tianjin, China
Abstract :
A novel method to form asymmetrically corrugated long period fiber gratings (LPFGs) by periodically scanning the unstripped optical fiber using the high-frequency CO2 laser under side illumination as well as HF etching processing has been proposed and demonstrated in this letter. Microbends exist in the asymmetric structures when tensile force is applied that greatly enhance the refractive index modulation. Several asymmetrically corrugated LPFGs with a grating pitch of 600 μm are fabricated. A linearly step-changed period chirped corrugated LPFG has also been fabricated that well proves the flexibility of this method in fabricating nonuniform corrugated LPFGs.
Keywords :
carbon compounds; diffraction gratings; etching; optical fibre cladding; optical fibre fabrication; optical modulation; refractive index; solid lasers; CO2; HF etching; asymmetric structures; asymmetrically corrugated LPFG; asymmetrically corrugated long period fiber gratings; etching cladding; fiber coating; grating pitch; high-frequency CO2 laser; linearly step-changed period chirped corrugated LPFG; microbends; nonuniform corrugated LPFG; refractive index modulation; side illumination; size 600 mum; tensile force; unstripped optical fiber; Chirp; Coatings; Fiber gratings; Fiber lasers; Force; Optical fiber sensors; Optical fibers; ${rm CO}_{2}$ laser; asymmetric; corrugated long-period fiber grating; etching; loss tunable;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2013.2275007
