Design of all-solid fluorotellurite fibers with near-zero-flattened dispersion profiles for mid-infrared optical frequency comb generation

Abstract

All-solid fluorotellurite fibers with near-zero-flattened dispersion profiles in the wavelength range of 1840–2140 nm are designed for mid-infrared optical frequency comb (OFC) generation. The fiber core materials are TeO2-BaF2-Y2O3 (TBY) glasses. The fiber cladding materials are fluoroaluminate and TBY glasses. By controlling the core diameter and the thickness of the thin annular fluoroaluminate or TBY glass, the fiber with the chromatic dispersion value between −0.3 and 0.32 ps nm km−1 in the wavelength range of 1840–2140 nm is achieved. Furthermore, we perform numerical simulations on mid-infrared OFC generation via four-wave mixing in the designed fiber. By using a 1980 nm laser with a pulse width of 1.28 ps and a peak power of 60 W as the pump source, OFC spectrum expanding from 1127 to 4942 nm is obtained in a 2 m long fiber, and the pulse width of the generated OFC is about 25 fs. By varying the repetition rate of the pump source, mid-infrared OFC with tunable mode spacing is generated in the designed fiber.