【作者】 许智雄；

【导师】 曾和平；

【作者基本信息】 华东师范大学 ， 光学， 2007， 硕士

【摘要】 宽带可调谐多波长纠缠对于量子信息在量子网络、原子存储以及量子界面等方面的进一步的发展至关重要。目前大多数的高度纠缠的光子对都是通过参量下转换的方法来实现。由于参量上转换在实验上受到很多限制，很难在同一个晶体或泵浦源中得到宽带可调谐的纠缠光子对，或者将纠缠光子对扩展到短波紫外区域。本论文主要围绕自发参量上转换和下转换产生紫外和可见区域可调谐的time-bin纠缠彩虹对的实验展开论述。主要包括以下三个方面：1．讨论了在二阶非线性介质的参量混频过程中的时空调制不稳定性造成了彩色圆锥辐射的产生，主要研究了飞秒脉冲倍频过程的调制不稳定性。同时在实验上研究了简并参量光散射蓝环。2．基于二阶非线性晶体中的连续和脉冲种子光注入的非共线光参量放大(NOPA)过程，同步实现了自发参量上转换和下转换，得到了紫外和可见区域可调谐的彩虹对。相关的自发参量上转换和下转换光子表现出光束亮度高、空间发散小以及在很宽频谱范围内可调谐等特点。所有过程可以通过一束连续光来控制，用全光学控制高度相关的高能量光子对。3．基于NOPA过程得到的紫外和可见区域可调谐彩虹对构建了多波长time-bin纠缠彩虹。首先，紫外彩虹和可见彩虹的光子具有一一对应的关系，形成相关的光子对。其次，通过搭建一个具有固定臂长差的干涉仪，控制泵光功率，实现多波长time-bin纠缠彩虹。更多还原

【Abstract】 Broadband tunable and multipartite entanglements are essential for further developments of quantum information applications, such as quantum network, atomic memory, and photonic interface of quantum bits. Though most highly entangled photon pairs have been generated by means of parametric down-conversion, it is difficult for parametric up-conversion process to implement the broadband tune ability or extend to short wavelength with the one nonlinear crystal or pump source, as parametric up-conversion has been thus far limited in experiments.This dissertation provides our experimental investigations for simultaneous spontaneous parametric up conversion and down conversion to generate time-bin entangled rainbows tunable in the ultraviolet and visible regions. Our research work can be summarized as followings.1. The generation of colored conical emission from modulation instability (MI) during nonlinear optical parametric process in quadratic media. This part includes the spatiotemporal MIs by means of second harmonic (SH) generation, quadratic nonlinear coupling between fundamental and SH fields, as well as the degenerate parametric light scattering.2. The generation of tunable correlated rainbow pairs, which results from some cascade non-collinear optical parametric amplification (NOPA) in a quadratic medium seeded with a continuous-wave (cw) and pumped with pulsed-wave. The correlated spontaneous up conversion and down conversion photons exhibits a high beam brightness, small spatial divergence, and broad spectral tunability. Such processes could be controlled by continuous-wave light beams for the all-optical control of highly correlated pairs of energetic photons.3. First observation of a continuously select multi-wavelength entangled photon pairs based on rainbow pairs in NOPA in the ultraviolet and visible regions. The multi-wavelength entangled photon pairs are formed and characterized with an interferometer with a fixed optical path length difference between its short and long arms. The pumping intensity shall be low enough to ensure negligible generation rate of more than one photon pairs so that the ultraviolet and visiblephoton pairs are concurrently generated at one of the two well-defined times.更多还原