孤子光脉冲的产生及其应用研究  

Soliton pulses in an erbium-doped fiber ring laser and its use in supercontinuum generation

作　　者：张书敏[1] 温虹[2] 吕福云[3] 左晓雪[1] 

机构地区：[1]河北师范大学物理科学与信息工程学院,石家庄050016 [2]河北建筑工程学院数理系,张家口075024 [3]南开大学物理科学学院,天津300071

出　　处：《物理学报》2007年第4期2191-2195,共5页Acta Physica Sinica

基　　金：河北省自然科学基金(批准号:F2006000183);河北省教育厅科研计划(批准号:2001241);河北师范大学博士科研启动基金(批准号:L2005B05)资助的课题.~~

摘　　要：利用非线性偏振旋转技术实现自起振被动锁模.在掺铒光纤环形腔激光器中产生了中心波长为1563.3nm、重复频率为12.5MHz、脉冲宽度为352.0fs、3dB光谱宽度为7.8nm的孤子光脉冲.采用该孤子光脉冲作为抽运光源,经掺铒光纤放大器放大后,输入到101m长的高非线性光子晶体光纤中,获得了20dB带宽约为240nm的超连续激光光谱.实验详细观测了光脉冲随抽运功率的变化及超连续激光光谱的形成过程,分析了其形成机理.研究表明:当抽运功率较低时,光谱加宽主要由高阶孤子的分裂引起;随着抽运功率的增加,高阶孤子分裂成基本孤子的数目逐渐增大,光谱进一步加宽;当抽运功率增加到受激拉曼散射的阈值时,受激拉曼散射成为光谱展宽的主要原因;抽运功率进一步增加时,受激拉曼散射、参量四波混频等非线性的共同作用将使光谱进一步加宽且变得光滑.We present a source of soliton pulses in an erbium-doped fiber ring laser. The passive mode-locking is achieved by using the nonlinear polarization rotation technique. The system generates 352 fs pulses with repetition rate of 12.5 MHz and the 3dB spectrum width of about 7.8 nm at the central wavelength of 1563.3 nm. A low-cost erbium-doped fiber amplifier is employed to boost the peak power of the pulses. Single-mode supercontinuum is obtained by passing the amplified pulses through a photonic crystal fiber with the length of 101 rim. Further more, we show the evolution process of the supercontinuum with different optical pump power. It is shown that, with the low-intensity femtosecond pulses, the spectrum broadening is caused by the fission of the higher-order solitons. With the increase of the pump power, the threshold of stimulated Raman scattering （SRS） is achieved, and the energy transfer through SRS spreads toward the long wavelength and the short wavelength sides. On further increasing the pump power, the coupling between SRS and parametric four-wave mixing will result in the appearance of waves with new wavelengths, and the spectrum will become broader and more smooth.

关 键 词：孤子光纤激光器 超连续 光子晶体光纤 

分 类 号：O437[机械工程—光学工程]