Low‐loss all‐solid antiresonant fiber for flat‐top beam generation.

We report a novel kind of antiresonant fiber for flat‐top beam generation with all‐solid configuration. The fiber core introduces a square antiresonance structure with low‐high‐low refractive index distribution, achieving homogenization of the beam profile through its light guidance on the optical field. Attributed to the antiresonant structure, the all‐solid antiresonant fiber transmits the flat‐top beam with very low confinement loss and large mode area. And it generates and transmits flat‐top beam with low loss in wavelength range from 1200 nm to 2200 nm. This would open up the application of antiresonance fiber in beam shaping. [ABSTRACT FROM AUTHOR]