Photon Duplication

将进行一项实验研究计划，以在实验室实现光子复制过程，这是一种新的过程，即将一束输入光束的光子统计复制到两束输出光束中，其中一束可以测量，而另一束则供进一步操作。从许多基本和应用的角度来看，这一进程是有意义的。从根本上说，光子复制是一种从未被观察到的现象；它需要在一种从未被探索过的状态下进行量子光学实验。它还导致了新的量子非破坏检测策略，这些策略是有效的，不需要大的泵功率或显式的相敏测量。从应用的角度来看，光子复制器可以在通信网络中用作透明的光学分路器。具体地说，我们建议分析光子复制的详细物理过程，并进行一个实验来演示这一过程。四波混频实验将在预测会发生光子复制的区域内进行。采用锁模调Q激光泵浦的CdTe薄片作为非线性介质。之所以选择CdTe，是因为它具有很大的三阶非线性，响应时间为亚纳秒。我们将使用我们开发的一种新的脉冲散粒噪声检测方案来测量光子关联。此外，我们还将探讨在非线性光波导中实现光子复制过程的途径。

An experimental research program will be undertaken to realize in the laboratory the process of photon duplication, a novel process in which the photon statistics of an input beam of light is duplicated into two output beams, one of which can be measured while leaving the other for further manipulation. This process is of interest from a number of standpoints that are both fundamental and applied. Fundamentally, photon duplication is a phenomenon that has never been observed; it requires quantum- optic experimentation in a regime that has never been explored. It also leads to novel quantum nondemolition detection strategies that are efficient and do not require largepump power or explicit phase-sensitive measurements. From an applied standpoint, a photon duplicator can be used in a communication network as a transparent optical tap. Specifically, we propose to analyze the detailed physics of photon duplication and to perform an experiment that will demonstrate the process. A four-wave mixing experiment will be carried out in a regime where photon duplication is predicted to occur. A platelet of CdTe, pumped by a mode- locked and Q-switched Nd:YAG laser, will be used as the nonlinear medium. CdTe is chosen because it has been shown to have a large third-order nonlinearity with a sub-nanosecond response time. Photon correlations will be measured using a novel pulsed shot-noise detection scheme that we have developed. In addition, we will investigate avenues toward implementation of the process of photon duplication in nonlinear optical waveguides.