Quantum-Enhanced Optical-Phase Tracking
Quantum-Enhanced Optical-Phase Tracking
复制标题
DOI：
10.1126/science.1225258
复制
发表时间：
2012-09
期刊：
影响因子：
56.9
通讯作者：
H. Yonezawa;D. Nakane;T. A. Wheatley;K. Iwasawa;S. Takeda;H. Arao;Kentaro Ohki;K. Tsumura;
中科院分区：
文献类型：
--
作者：
H. Yonezawa;D. Nakane;T. A. Wheatley;K. Iwasawa;S. Takeda;H. Arao;Kentaro Ohki;K. Tsumura;
在光干涉仪或光通信中，信息通常以波形或光脉冲的相位存储。然而，波动和噪声会引起光脉冲的相位和幅度的随机抖动，使得跟踪相位变得困难。Yonezawa等人（第1514页）开发了一种基于量子力学压缩的技术，以确定随机变化的光学波形的相位。量子力学技术提高了确定相位的精度，随着光学技术的不断小型化，它应该有助于计量学的应用。发展了一种增强光子相位跟踪的量子力学技术。跟踪随机变化的光学相位是计量学中的关键任务，在光通信中具有应用。迄今为止，光学相位跟踪的最佳精度一直受到相干光的量子真空波动的限制。在这里，我们通过使用相位压缩量子态中的连续光束来超越这种相干态的限制。与以前的挤压增强计量学不同，由于海森堡的不确定性原理，仅限于具有非常小变化的相位，因此对于有限程度的挤压实现了最佳跟踪精度（对于固定的光强度）。通过优化压缩，我们跟踪相位的均方误差低于相干态极限15 ± 4%。
Keeping Track of Photon Phase In optical interferometers or optical communications, information is often stored in terms of the phase of the waveform or light pulse. However, fluctuations and noise can give rise to random jitter in the phase and amplitude of the optical pulses, making it difficult to keep track of the phase. Yonezawa et al. (p. 1514) developed a technique based on quantum mechanical squeezing to determine the phase of randomly varying optical waveforms. The quantum mechanical technique enhanced the precision with which the phase could be determined and, as optical technologies continue to be miniaturized, should be helpful in applications within metrology. A quantum mechanical technique is developed to enhance the phase tracking of photons. Tracking a randomly varying optical phase is a key task in metrology, with applications in optical communication. The best precision for optical-phase tracking has until now been limited by the quantum vacuum fluctuations of coherent light. Here, we surpass this coherent-state limit by using a continuous-wave beam in a phase-squeezed quantum state. Unlike in previous squeezing-enhanced metrology, restricted to phases with very small variation, the best tracking precision (for a fixed light intensity) is achieved for a finite degree of squeezing because of Heisenberg’s uncertainty principle. By optimizing the squeezing, we track the phase with a mean square error 15 ± 4% below the coherent-state limit.