中文摘要：

利用单模光纤中的光弹效应和交叉相位调制（XPM）效应，提出了一种频率分辨光学开关法测量超短脉冲的新方案。在本方案中，单模光纤的前一部分产生可变延迟，后一部分作为非线性介质产生非线性效应。该方案只需一根单模光纤，无须复杂的光路校准，结构简单，损耗低；光纤中的XPM效应易发生，无须相位匹配。对提出的方案进行了数值模拟，采用基于矩阵的主元素广义投影算法，恢复出待测脉冲的幅度和相位信息，并研究了光纤长度和待测超短脉冲的脉冲宽度对测量结果的影响。结果表明：测量准确度随着光纤长度的增加而提高，选取长度为2 km的光纤，就可以实现对超短脉冲的准确测量；本文方案适用于脉冲宽度不小于80 fs的超短光脉冲的测量。

英文摘要：

A new scheme of measuring ultra-short optical pulses, based on the photo-elastic effect and cross-phase modulation （XPM） effect in a single-mode fiber, is proposed. In this novel scheme, a variable delay is generated in the former part of the single-mode fiber, and the nonlinear effect is produced in the latter part as a nonlinear medium. The structure including only one single-mode fiber is very simple and low-cost, and needs no complex optical circuit calibration. In addition, XPM effect in the fiber can be realized easily without phase matching. Measured pulses can be retrieved by using principal component generalized projects algorithm based on matrix, and the influences of fiber length and the pulse width on amplitude and phase are studied by numerically simulating the scheme proposed. The results show that the ultra-short optical pulses can be measured when fiber length is equal to 2 km, and the accuracy of measurement is improved by increasing the fiber length. The proposed scheme can realize the measurement of optical ultra-short pulse whose pulse width is above 80 fs.