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.