Bài báo khoa học

We numerically investigate novel As2S3 circular lattice photonic crystal fibers (PCFs) with an effective mode area and confinement loss appropriate for each specific application. This is carried out by keeping the filling factor unchanged from the second ring onwards while that of the first one changes in a step of 0.05. The decrease of the effective mode area leads to a larger confinement loss characteristic. At 2.5 µm wavelength, most structures have very low confinement loss and their value does not exceed 10-17 dB/m. The fiber with lattice constant Ʌ = 2.5 µm and filling factor d1/Ʌ = 0.3 has the highest effective mode area of 11.94 µm2, which will be useful for high-power applications. Conversely, the minimum value of the effective mode area is observed in the case Ʌ = 1.0 µm and d1/Ʌ = 0.8, equal to 1.16 µm2. PCFs with a small effective mode area increase the nonlinear coefficient of the fiber and therefore have great potential in supercontinuum generation.