Optical Communication in the Quantum Limit: Noise-Free Optical Amplifiers and Taps

光纤通信系统的性能从根本上受到光的放大和截取过程中的量子力学波动的限制。可达到的最小总噪声受海森堡最小不确定积的限制。这项工作的目标是开发能够规避量子力学限制的光电器件。这是通过重新分配可观测值中的不确定性来实现的，从而使系统性能的兴趣量显示出最小的噪声。同时，共轭观测值的噪声增强。利用光子数放大器和抽头，光信号强度中编码的信息可以以很小的不确定性被放大和测量，而相位信息则被破坏而变得完全不确定。提出的工作将强调制造实用的半导体器件，这将允许几乎无噪声的放大和信息挖掘和产生。该项目的成功依赖于制造和集成不同配置的高量子效率半导体激光器的能力。除了制造方面的努力，大量的工作将驻留在实验验证这些器件的低量子噪声特性。我们提出要演示的无噪音水龙头和放大器有望在需要在许多订阅者之间共享信息的应用程序中产生强大的影响。这就是光互连和局域网的情况：如果这里开发的设备得以实施，每个用户将能够测量、放大和再生进一步使用的信息，而不会降低信号质量。此外，这些设备的多功能性，包括将信号克隆成许多量子相关副本的可能性，以及自由选择后者的发射波长的可能性，可能在空间和波分复用应用中具有吸引力。＊＊＊

9634542 Coldren The performance of fiber-optic communications systems is fundamentally limited by quantum mechanical fluctuations in the processes of amplification and tapping of light. The minimum attainable total noise is limited by Heisenberg's minimum uncertainty product. The goal of the proposed work is the development of optoelectronic devices that would circumvent the quantum mechanical limits. This is done by the redistribution of the uncertainty in the observables such that the quantity of interest for the system performance exhibits a minimum noise. At the same time the noise of the conjugate observable is enhanced. By means of photon number amplifiers and taps, the information encoded in the intensity of an optical signal can be amplified and measured with very little uncertainty at the expense of phase information which is destroyed and becomes totally uncertain. The proposed work will emphasize the fabrication of practical semiconductor devices that will allow for virtually noiseless amplification and information tapping and generation. The success for this project relies on the ability to fabricate and integrate different configuration of high quantum efficiency semiconductor lasers. In addition to the fabrication efforts, considerable work will reside in the experimental verification of the low quantum noise properties of these devices. Noiseless taps and amplifiers that we propose to demonstrate are expected to have a strong impact in applications where information needs to be shared among many subscribers. This is the case in optical interconnects and local-area networks: If the devices developed here are implemented, each subscriber will be able to measure, amplify, and regenerate the information of further use without degrading the signal quality. Further, the versatility of these devices, which includes the possibility of cloning a signal into many quantum correlated copies, and the possibility of choosing freely the emission wavelength of the latter, may be attractive in space- and wavelength-division multiplexing applications. ***