No abstract

We report a large mode area photonic crystal fiber with a top-hat mode field. The optical fiber has a multi-layer square structure with air holes and doped layer. A flat and top-hat-like mode intensity profile is provided through the reasonable design of the doped layer. The modal characteristics including effective mode area, dispersion and confinement loss are investigated. The proposed fiber with a top-hat mode generation may have potential applications in laser drilling, laser cleaning, imaging, spectroscopy, and so on.

No abstract

We report a large mode area photonic crystal fiber with a top-hat mode field. The optical fiber has a multi-layer square structure with air holes and doped layer. A flat and top-hat-like mode intensity profile is provided through the reasonable design of the doped layer. The modal characteristics including effective mode area, dispersion and confinement loss are investigated. The proposed fiber with a top-hat mode generation may have potential applications in laser drilling, laser cleaning, imaging, spectroscopy, and so on.

We report a ring-assisted few-mode fiber design with large mode effective index difference (△n eff ) and low loss. By introducing the low-index ring-assisted structure in the cladding, the effective indexes of LP 11 , LP 21 and LP 02 modes can be greatly reduced, while the effective index of LP 01 mode is almost unaffected. Also, we find that introducing multiple ring-assisted structures will help reduce loss. The proposed few-mode fiber has potential application value for improved mode-division multiplexing optical fiber communication system.