Underwater Bessel-like beams with enlarged depth of focus based on fiber microaxicon

Underwater optical wireless communication, which is useful for oceanography, environmental monitoring, and underwater surveillance, suffers the limit of the absorption attenuation and Mie–Rayleigh scattering of the lights. Here, Bessel-like beams generated by a fiber microaxicon is utilized for underwater wireless propagation. Underwater, the cone angle for generating Bessel-like beams starts from 46°, which is smaller than that in air for Bessel-like beams. When the cone angle of the fiber micr...