Cong Guangwei, Ohno Morifumi, Maegami Yuriko, Okano Makoto, Yamada Koji
Opt Express. 2016 Dec 26;24(26):29452-29458. doi: 10.1364/OE.24.029452.
Optical autocorrelation accuracy was for the first time analyzed for the silicon waveguide based autocorrelators utilizing two-photon absorption (TPA) under various short pulse conditions by numerical simulation. As for autocorrelation operation in the sub-μm silicon p-i-n rib waveguides on the 220 nm SOI (silicon on insulator) wafers, the autocorrelation error of pulse width measurement gradually increases with the increase of the peak power for both Gaussian and hyperbolic secant pulses due to the influence of free-carrier absorption (FCA). For the same pulse type, the relative error is independent of the input pulse width; however different pulse type has different peak power dependency of the accuracy. It was verified that this thin rib waveguide has a TPA responsivity >60 times higher than the thick rib waveguides and the correct pulse width can be measured with a <1% relative error for characterizing ps/sub-ps short pulses of sub-watt peak powers by utilizing the silicon wire p-i-n waveguides as the autocorrelator detector.
通过数值模拟首次分析了在各种短脉冲条件下基于硅波导的利用双光子吸收（TPA）的自相关器的光学自相关精度。对于在220nm绝缘体上硅（SOI）晶圆上的亚微米硅p-i-n肋形波导中的自相关操作，由于自由载流子吸收（FCA）的影响，对于高斯脉冲和双曲正割脉冲，脉冲宽度测量的自相关误差都随着峰值功率的增加而逐渐增大。对于相同的脉冲类型，相对误差与输入脉冲宽度无关；然而，不同的脉冲类型具有不同的精度峰值功率依赖性。已证实，这种薄肋形波导的TPA响应率比厚肋形波导高60倍以上，并且通过使用硅线p-i-n波导作为自相关器探测器，对于表征亚瓦峰值功率的皮秒/亚皮秒短脉冲，可以以小于1%的相对误差测量正确的脉冲宽度。
