Granzow N, Stark S P, Schmidt M A, Tverjanovich A S, Wondraczek L, Russell P St J
Max Planck Institute for the Science of Light, Guenther-Scharowsky Str. 1, 91058 Erlangen, Germany.
Opt Express. 2011 Oct 10;19(21):21003-10. doi: 10.1364/OE.19.021003.
We explore the use of a highly nonlinear chalcogenide-silica waveguide for supercontinuum generation in the near infrared. The structure was fabricated by a pressure-assisted melt-filling of a silica capillary fiber (1.6 µm bore diameter) with Ga4Ge21Sb10S65 glass. It was designed to have zero group velocity dispersion (for HE11 core mode) at 1550 nm. Pumping a 1 cm length with 60 fs pulses from an erbium-doped fiber laser results in the generation of octave-spanning supercontinuum light for pulse energies of only 60 pJ. Good agreement is obtained between the experimental results and theoretical predictions based on numerical solutions of the generalized nonlinear Schrödinger equation. The pressure-assisted melt-filling approach makes it possible to realize highly nonlinear devices with unusual combinations of materials. For example, we show numerically that a 1 cm long As2S3:silica step-index fiber with a core diameter of 1 µm, pumped by 60 fs pulses at 1550 nm, would generate a broadband supercontinuum out to 4 µm.
我们探索了一种用于近红外超连续谱产生的高度非线性硫族化物 - 二氧化硅波导。该结构是通过用Ga4Ge21Sb10S65玻璃对二氧化硅毛细管光纤（内径1.6 µm）进行压力辅助熔体填充来制造的。其设计目的是在1550 nm处具有零群速度色散（对于HE11芯模）。用掺铒光纤激光器发出的60 fs脉冲泵浦1 cm长的波导，对于仅60 pJ的脉冲能量，会产生倍频程跨度的超连续谱光。基于广义非线性薛定谔方程的数值解，实验结果与理论预测之间取得了良好的一致性。压力辅助熔体填充方法使得实现具有非同寻常材料组合的高度非线性器件成为可能。例如，我们通过数值计算表明，一根1 cm长、芯径为1 µm的As2S3:二氧化硅阶跃折射率光纤，在1550 nm处用60 fs脉冲泵浦，将产生延伸至4 µm的宽带超连续谱。
