Application of ethanol infiltration for ultra-flattened normal dispersion in fused silica photonic crystal fibers

Le H-V, Cao V-L, Nguyen H-T, Nguyen A-M, Buczyński R. and Kasztelanic R.

Laser Physics

28(11), 2018, art. 115106, doi.org/10.1088/1555-6611/aad93a

This paper proposes a new design for an ultra-flattened normal dispersion photonic crystal fiber (PCF) with ethanol infiltration. The optimization process allow us to achieve a symmetric ultra-flat (1 ps/nm/km) normal dispersion in the range of over 500 nm, which is not possible with standard air hole silica fiber. This fiber allows for supercontinuum (SC) generation in the normal dispersion regime. Numerical simulations show that a PCF fiber of length 20 cm, with the pump wavelength of 1550 nm, pulse energy of 4 nJ and duration of 80 fs can generate 945 nm of flattened broadband SC spectrum in the infrared wavelength range; the output pulse peak is also very stable. In addition, the same optical fiber with air holes and under the same stimulated conditions generates the SC spectrum in the anomalous dispersion regime. The proposed PCF structure could be very helpful in large-scale engineering applications, such as dispersion compensation, ultra-short soliton pulse propagation, spectroscopy applications etc.