Unit Quantum Efficiency, Nondestructive, Photon Counting Detector

EIA-0323463 John Howell罗切斯特大学单位效率，非破坏性，光子计数探测器导致光的急剧减慢和停止的惊人行为在量子信息领域也有希望。 根据施密特和伊玛莫格鲁的理论建议，目前正在建造一种超灵敏的光子计数探测器。 这个实验的核心是电磁感应透明（EIT）。 EIT允许与原子跃迁共振的激光束（探测束）无衰减地穿过相关原子的原子气体。 然而，当信号光束通过样品时，EIT效应发生了显著变化。 这种效应是如此强烈，以至于信号场中的单光子可以改变经典探测光束的宏观性质，如相位和衰减。 高效率的非破坏性光子计数是许多量子通信协议的极大兴趣。实验处于建设阶段。 正在开发的电子设备将允许两个新焦点涡旋激光器，一个作为探测场，另一个作为耦合场，被锁定在Rb 87的无多普勒饱和吸收光谱中的共振峰的顶部。 努力是实现100 KHz量级或更好的两个激光器的线宽稳定性。 然后，锁定的激光器将几乎共线地通过相对高缓冲气体密度的蒸气室。 两个信号光子源正在生产中。 第一源来自第三显著衰减的二极管激光器。 探测器将把信号激光的泊松分布投射到纯数态，这本身就是一个令人兴奋的结果。 第二个来源是窄带纠缠光子。 与探测器的建造同时进行的，是一个窄带锁频纠缠光子源，这是该探测器测试的重要组成部分。 两名妇女、三名西班牙裔学生和一名非洲裔美国学生正在该项目下接受培训。研究人员还积极参与本科生研究经验（REU）和本科教学。

EIA-0323463John HowellUniversity of RochesterUnit Efficiency, nondestructive, photon counting detectorThe startling behaviors that have led to the dramatic slowing and stopping of light also have promise in the field of quantum information. Following a theoretical proposal by Schmidt and Imamoglu, an ultra-sensitive photon-counting detector is currently under construction. At the heart of this experiment is electromagnetically induced transparency (EIT). EIT allows a laser beam (probe beam), on resonance with an atomic transition, to pass unattenuated through an atomic gas of the relevant atoms. However, when a signal beam passes through the sample the EIT effects are dramatically changed. The effects are so strong that single photons in the signal field can change the macroscopic properties such as phase and attenuation of a classical probe beam. Nondestructively counting photons with high efficiency is of great interest to many quantum communications protocols. The experiment is in the construction phase. The electronics are being developed that will allow two New Focus Vortex lasers, one as the probe field and the other as the coupling field, to be locked to the top of a resonance peak in a Doppler-free saturated absorption spectrum of Rb 87. The effort is to achieve a linewidth stability on the order of 100 KHz or better for both lasers. The locked lasers will then be nearly collinearly passed through a relatively high buffer gas density vapor cell. Two sources for the signal photons are in production. The first source is from a third dramatically attenuated diode laser. The detector will project the otherwise Poissonian distribution of the signal laser into pure number states, which is an exciting result in and of itself. The second source is from narrow band entangled photons. Concurrent with the construction of the detector, is a narrow-band frequency-locked source of entangled photons, which is an important part of the test of this detector. Two women, three Hispanic and one African-American students are being trained under this project. The investigators are also heavily involved in Research Experiences for Undergraduates (REU) and undergraduate teaching.