【作者】 张秀婷；

【导师】 李小英；

【作者基本信息】 天津大学 ， 光学工程， 2013， 硕士

【摘要】 关联光子对是揭示量子力学基本定律和实现量子信息处理的重要资源，基于光纤的1550nm通讯波段关联光子源具有体积小、易于实现、能够与现有光纤系统完全兼容等优点而受到关注，这种关联光子源的原理是利用脉冲激光泵浦色散位移光纤，引起自发四波混频效应来产生关联光子对。高性能、结构紧凑的脉冲光纤激光器是实现关联光子源的关键因素。本文搭建了一台全光纤锁模脉冲激光器，并研究了其在关联光子源中的适用性。论文中基于非线性偏振旋转效应使用单个偏振控制器搭建了一台掺铒光纤脉冲激光器，得到了稳定的被动锁模脉冲序列，并观察到了多种谐波锁模现象。该激光器中心波长分别位于短波长处的1533.7nm和长波长处的，激光脉冲重复频率为20.21MHz，最大输出功率达5.4mW,短波长处测得脉冲宽度528fs，时间带宽积0.47，约为高斯脉冲傅里叶变换极限的1.1倍。对该泵浦源下的关联光源进行了单通道光子计数率和符合计数率的测量，并利用单光子探测器对激光脉冲对比度进行了测量，展示了该激光器在量子关联光源中的适用性。本文的主要内容安排如下：首先，对光纤激光器的基本结构、原理、特点以及分类做了详细的介绍，解释了掺铒光纤的特性并说明了量子关联光源对泵浦光的需求；然后，依据上述基本理论搭建了单偏振控制器的锁模脉冲激光器，并对其输出特性做了研究与分析；最后，测量了该激光器泵浦下获得的关联光子的单通道光子计数率以及符合计数率，并对激光器的脉冲对比度进行了理论分析与实验测量，证明该激光器能够为量子关联光源提供有效泵浦。更多还原

【Abstract】 Correlated photon pairs is an important resource to reveal the fundamental laws of quantum mechanics and quantum information processing, the quantum correlated photon source in1550nm based on optical fiber communication band drew attention for it’s small size, easy to implement, and fully compatible with existing fiber-optic systems, the principle of which is with pulse laser pumping the dispersion-shifted fiber, the correlated photons were generated by spontaneous four-wave mixing. High-quality and compact pulsed fiber laser is a key factor of correlated photon sources, so an all-fiber mode-locked pulse laser was set up in this paper, with it’s applicability in the correlated photon source was studied.In the thesis, a pulsed erbium-doped fiber pulse laser with single polarization controller was built based on the nonlinear polarization rotation, which output is stable passively mode-locked pulse train, and a variety of harmonic mode-locked phenomenon was observed. The center wavelength of the laser are located at1533.7nm and1558.7nm, with the repetition rate20.21MHz, maximum output power8.5mW, the measured pulse width is528fs, the time-bandwidth product is0.47, which is about1.1times high of the Gaussian pulse Fourier transform limit. We measured its single-channel photon counting rate and coincidence count pumped by this laser, the laser’s pulse contrast ratio was also measured, all measurement showed the well applicability of the laser in the quantum correlated source.The main contents of the thesis are as follows:First, introduce details of fiber laser, including the basic structure, the principles, characteristic and classification, explaining the characteristic of the erbium-doped fiber, and the source’s demands for pump light; then a single polarization controller mode-locked pulse laser was built based on the top theory, and studied its output characteristic; finally, measured the single-channel photon count rate and coincidence counting rate of the correlated photons, and did theoretical analysis and experimental measurement in the pulse contrast of the laser, which proved that the laser provided an effective pump for the quantum correlated source.更多还原