Laser beam shaping using a single-mode fiber abrupt taper.
A new beam-shaping device was realized by an abrupt taper with a length of approximately 700 microm and a waist of approximately 40 microm. The insertion loss of the device is less than 3%. The diameter of the flat beam top can be up to approximately 900 microm with a small intensity variation (4%) and a small half-divergence angle (2.5 degrees). The conversion efficiency of the new device from a Gaussian-shaped to a flat-top profile is comparable with that of a long-period-gratings-based device, while keeping the fabrication cost low. The new device requires only a fusion splicer and standard SMF-28 fiber, eliminating the need for photolithographic procedures. The new device also has no obvious incident light polarization dependence.
Tian
Zhaobing
Z
Department of Physics, Engineering Physics, and Astronomy, Queen's University, Kingston, Ontario, Canada. tianzhaobing@gmail.com
Nix
Michael
M
Yam
Scott S-H
SS