基于液体纤芯光子晶体光纤的低阈值受激拉曼散射

为了研究微结构光纤在光流体技术中的应用,在空芯光子晶体光纤(hollow-core photonic crystal fiber,HCPCF)纤芯中充入四氯化碳(CCl_4)制成液芯光学微池,用1 064 nm的光源泵浦,测量CCl_4的受激拉曼散射特性.利用包层孔塌缩技术将纤芯直径10μm,长1.8 m的HC-PCF两端包层孔堵住,CCl_4在毛细作用力及外部压力下充满纤芯,其后将两端切去,由于包层空气孔的有效折射率(约1.1)低于CCl_4(约1.45),保证了全反射原理导光.用中心波长1064 nm,重复频率200 kHz,脉宽186ps,可调谐输出功率为0~1 W的光纤激光器作为泵浦源,泵浦CCl_4液芯光纤产生了两级拉曼斯托克斯谱线输出,分别在1118、1172.3 nm处.通过调节泵浦功率测得一阶拉曼阈值对应的峰值功率为0.94 kW.结果表明:微结构光纤是光流体技术的良好载体.

Low-threshold Stimulated Raman Scattering Based on Liquid-filled Hollow-core Photonic Crystal Fiber

To study the application of microstructure optical fiber in optofluidic technology, the HC-PCF with carbon tetrachloride ( CCl4 ) was filled and pumped with a 1 064 nm pulsed laser to generate the stimulated Raman scattering. By collapsing the cladding holes, CCl4 can be filled only in the core of the 1. 8 m long, 10μm core diameter HC-PCF by capillary forces and external pressures. The light is guided by total internal reflection since the effective refractive index of cladding air holes ( about 1. 1 ) is lower than CCl4(about 1. 45). The 1 064 nm pump laser has a repetition rate of 200 kHz, a pulse width of 186 ps and a tunable output power of 0 ～1 W. Two orders of Stokes line are generated at 1 118 nm and 1 172. 3 nm. By adjusting the pump power, the corresponding peak power of first-order Raman threshold is 0. 94 kW. Results show that the microstructure optical fiber is a good carrier for optofluidic technology.