Title :
Generation of Optical Vortices Using a Helical Fiber Bragg Grating
Author :
Zhongxi Lin ; Anting Wang ; Lixin Xu ; Xiaoqiang Zhang ; Biao Sun ; Chun Gu ; Hai Ming
Author_Institution :
Dept. of Opt. & Opt. Eng., Univ. of Sci. & Technol. of China, Hefei, China
Abstract :
We present an effective method to generate optical vortices (OVs) by using a helical fiber Bragg grating (H-FBG) written directly on the few-mode fiber. The helical index modulation is obtained by rotating fiber during single-side UV exposure using a phase mask. A set of coupled-mode equations are formulated to analysis reflection characteristics of the H-FBG. We propose that stable OVs can be achieved with a proper design M-fiber, and the order of the OVs can be adjusted by tuning the resonant wavelength and the handedness of the H-FBG.
Keywords :
Bragg gratings; coupled mode analysis; masks; optical design techniques; optical fibre fabrication; optical modulation; optical vortices; H-FBG; coupled-mode equations; few-mode fiber; helical fiber Bragg grating; helical index modulation; optical vortex generation; phase mask; reflection characteristics; resonant wavelength; rotating fiber; single-side UV exposure; Couplings; Fiber gratings; Indexes; Laser modes; Optical fibers; Optical vortices; Bragg grating; M-fiber; helical fiber; modes coupling; optical vortices (OVs); orbital angular momentum (OAM); wavelength filter;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2014.2320539
