CAJ | 학술논문

采用分步傅里叶方法,对飞秒脉冲在高非线性光纤中超连续谱(SC)的形成过程进行了研究,分析了脉冲峰值功率,脉冲宽度及初始频率啁啾对超连续谱特性的影响.结果表明,脉冲峰值功率,脉冲宽度以及初始啁瞅对超连续谱的形成有着极其重要的影响;当脉冲峰值功率逐渐增大,超连续谱随之愈宽(-20 dB处谱宽从170 nm展宽到400 nm以上),平坦度愈好.与之相反,脉冲宽度逐渐增大,超连续谱展宽范围减小,其平坦度也逐渐劣化;初始负啁啾有利于脉冲SC谱的展宽而正啁啾使脉冲SC谱的展宽受到一定抑制.进一步研究表明,适当的峰值功率超短啁啾脉冲在高非线性光纤传输时,得到没有泵浦成份残余的超宽且平坦超连续谱.
채용분보부리협방법,대비초맥충재고비선성광섬중초련속보(SC)적형성과정진행료연구,분석료맥충봉치공솔,맥충관도급초시빈솔조추대초련속보특성적영향.결과표명,맥충봉치공솔,맥충관도이급초시조추대초련속보적형성유착겁기중요적영향;당맥충봉치공솔축점증대,초련속보수지유관(-20 dB처보관종170 nm전관도400 nm이상),평탄도유호.여지상반,맥충관도축점증대,초련속보전관범위감소,기평탄도야축점열화;초시부조추유리우맥충SC보적전관이정조추사맥충SC보적전관수도일정억제.진일보연구표명,괄당적봉치공솔초단조추맥충재고비선성광섬전수시,득도몰유빙포성빈잔여적초관차평탄초련속보.
The supercontinuum generation in high nonlinear fiber with the normal dispersion is investigated using the split-step Fourier method. The effect of the peak power of pump pulse, pulse width and the frequency chirp on characteristics of supercontinuum spectrum is analyzed. The results show that the pulse width, peak power and initial chirp of the pump pulse are very important to flat wideband supercontinuum generation. With the increase of the peak power, the spectral width becomes wider (170 nm to more than 400 nm at -20 dB) and the flatness of supercontinuum becomes better. By contrast, the spectral width becomes narrower and the flatness of supercontinuum becomes worser when the pulse width increases gradually. The negative initial chirp is profitable for spectrum broadening, but the positive chirp has certain impact on spectrum broadening. It is further investigated that a broadband and fiat supercontinuum without residual pump is generated from such a high nonlinear fiber pumped at the normal dispersion region.