Study On Mid-ir Supercontinuum Generation From As₂S₃ Photonic Cr Ystal Fibers

Mid-IR supercontinuum is widely used in many different fields such as Industrial manufacturing, communication technologies and medical technology because of its high brightness and wide spectrum. However, pohotonic crystal fiber(PCF) has more changeable structure & material than common fiber, which brings more attaention. Compared to other Drawn PCF material, chalcogenide glasses not only has good physical and chemical stability, but also has good infrared transmission characteristics and high nonlinear. As2S3 chalcogenide glasses could draw more sable physical performance and lower cost which is well suited for band width of the supercontinuum. At present, it has become research focus by using As2S3 PCF supercontinuum generation in supercontinuum fieldsThis paper uses split-step fourier method to solve the nonlinear Schrodinger equation and femtosecond laser transmission process in the PFC which may let us observe the phenomenon of continuous spectrum directly.Firstly, this paper presented a new total internal reflection As2S3 PCF with low loss and high nonlinear. We research transmission process of femtosecond laser in the PCF to realize output of wider mid-IR supercontinuum by means of split-step fourier method to solve the nonlinear Schrodinger equation. We use full vectorial finite element method simulate the effects of dispersion, loss and nonlinearity transmission characteristics by big round duty cycle, small round duty cycle, cladding layers and Lattice Constant in this total internal reflection As2S3 PCF. Simulate the transmission progress in femtosecond laser, we analyze the femtosecond laser width, peak power and PCF length have the influence on supercontinuum spectrum generation. At the same we analyze its physical mechanisms and optimize its performance to get mid-IR supercontinuum of a 2-8μm wavelength bandwidthSecondly, this paper present a new photonic-bandgap As2S3 PCF and analyze that duty cycle, cladding layers and lattice constant of photonic-bandgap As2S3 PCF have an impact on Optical band gap range, postion, dispersion, loss and nonlinearity transmission characteristics. We analyze photonic bandgap effect impacts on Supercontinuum generation via numerical simulation of transmission progress in femtosecond laser and we gain 2-8μm wavelength bandwidth mid-IR supercontinuum of controllable widening range and position.