中红外硫系光子晶体光纤参量放大特性模拟研究

Simulation study of chalcogenide glass photonic crystal fiber parametric amplifier in mid-IR

硫系玻璃具有良好的红外透过性能（可达25μm），极低的声子能量（＆lt;350 cm-1），较大的玻璃形成区和极高的非线性折射率n2（为石英材料的100~1000倍）。硫系玻璃光子晶体光纤因其优良的非线性特性在红外波段具有众多的潜在应用价值。设计一种高非线性特性的无As环保型的Ge20Sb15Se65硫系玻璃光子晶体光纤，利用平面波展开法对结构参数进行优化，获得了具有高非线性和宽带色散平坦的光纤结构参数，研究了其光学参量放大过程。数值模拟发现，通过调整光纤的色散零点，利用3.4μm激光泵浦，可对3.3~3.5μm波段信号光实现有效放大。

Chalcogenide glasses were possessed of some unique advantages, such as large infrared transmission window（up to 25μm）, low phonon energy（lower than 350 cm-1）, large glass forming region and highly nonlinear refractive coefficient n2 （about 100-1 000 times than silica）. With excellent optical nonlinear,calcogenide glass photonic crystal fiber had a large number of potential applications in the infrared filed. A highly nonlinear photonic crystal fiber based on Ge20Sb15Se65 chalcogenide glass was designed. Using plane-wave method （PWM）, numerical analysis of its nonlinear and dispersion characteristics with different structure parameters were carried out. By optimization structural parameters, a highly nonlinear and broadband dispersion-flattened fiber was obtained. With a 3.4μm laser pumping, signal light could be effectively amplified in 3.3-3.5μm.