Laser beam shaping using a single-mode fiber abrupt taper.

Department of Physics, Engineering Physics, and Astronomy, Queen's University, Kingston, Ontario, Canada.
Optics Letters (Impact Factor: 3.18). 03/2009; 34(3):229-31. DOI: 10.1364/OL.34.000229
Source: PubMed

ABSTRACT 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.

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