利用双零色散点窄反常色散带光纤制备高相干中红外超连续谱OA

This paper proposes a germanium-core silicon-cladding photonic crystal fiber with a hexagonal lattice structure.An improved Grey Wolf optimization algorithm is employed for the inverse design of the fiber's structure parameters,yielding a narrow anomalous dispersion band(5.196-7.544 µm)bounded by two zero-dispersion wavelengths in the mid-infrared region.Numerical simulations demonstrate that under femtosecond pulse pumping with a peak power of 2 kW,a pulse width of 100 fs at the wavelength of 5.5 µm,the fiber can generate a broadband mid-infrared supercontinuum covering 3 µm to 10 µm.Under the mixed noise model incorporating 1%amplitude fluctuation,anti-correlated pulse duration jitter,and quantum noise,the average first-order complex degree of coherence for the generated mid-infrared supercontinuum can be maintained at 98.27%.This study confirms the feasibility of generating broadband,highly coherent mid-infrared supercontinuum by pumping ultrashort pulses within the narrow anomalous dispersion band of silicon-germanium fibers,providing a promising light source solution for applications in mid-infrared optical frequency combs and precision spectroscopy.