共查询到18条相似文献,搜索用时 78 毫秒
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平衡零拍探测器的改进 总被引:1,自引:0,他引:1
平衡零拍探测技术是连续变量量子信息科学研究中测量量子态量子噪声的最佳方法之一。在平衡零拍探测系统中,需要一对性能和结构尽量相同的光电探测器,以便很好地减去经典噪声,有效探测散粒噪声基准及光场噪声。根据基尔霍夫电流定律及光电二极管串联的办法,设计并制作出一种性能优良的低噪声平衡零拍探测器。该探测器从光电二极管串联节点处取出光电流相减信号,然后对信号进行放大,在对两探测器全同性要求降低的同时提高了平衡零拍探测的性能。实验结果表明,该探测器在2MHz处共模抑制比达39dB,能很好地满足量子信息对低噪声、线性增益及高共模抑制比的要求。 相似文献
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低频压缩态光场可用于提高引力波探测器灵敏度, 近年来受到人们的广泛关注. 相对于高频段而言, 低频压缩态的产生更容易受到外界环境噪声的干扰而不易被观察到. 本文采用全固化单频倍频Nd: YVO4/KTP激光器作为光源, 利用双波长共振的光学参量振荡器实现参量过程, 以1064 nm波长的红外作为基频光, 激光器腔内倍频产生的532 nm绿光作为抽运光, 通过调节周期性极化磷酸氧钛钾晶体温度使光学参量振荡器达到双波长同时共振, 采用真空注入的方式, 利用Pound-Drever-Hall锁腔技术锁定抽运场. 输出压缩光通过平衡零拍探测, 最终在实验上获得了频率低至3 kHz的真空压缩, 所直接观察到的压缩度为2 dB. 相似文献
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设计了一套可以用来测量弱脉冲光时域噪声信息的平衡零拍探测系统,通过对本底光散粒噪声基准的测量分析了该系统的各项性能指标,并且对弱相干光脉冲进行了正交位相振幅分量的噪声测量。 相似文献
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相干态光场的位相统计性质 总被引:5,自引:0,他引:5
根据Pegg-Barnett位相定义,计算了相干态光场的位相概率分布函数,并且进行了数值模拟。研究表明在真空态时,位相分布曲线为一条直线;相干态下位相分布曲线表现为:均匀分布→泊松分布→均匀分布。 相似文献
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时域脉冲平衡零拍探测器能够直接对光场量子态的正交分量进行测量, 是连续变量量子密钥分发系统的核心测量器件, 其测量精度与密钥分发系统的额外噪声及安全密钥速率密切相关. 本文理论分析了探测器双臂不平衡对测量精度的影响, 实验设计并研制了双臂可精确自动平衡的时域脉冲平衡零拍探测器. 通过高精度控制探测器一臂的光纤圆环曲率半径, 实现了光纤内部光场强度的精密衰减, 进而获得了探测器的精确自动平衡. 实验测试结果表明时域平衡零拍探测器双臂具有10-5以上的平衡精度, 能够长时间稳定运行, 有效避免了探测器的输出电压进入非线性区或饱和区. 该探测装置可应用于连续变量量子密钥分发系统, 有效降低由于量子态信号探测过程引入的额外噪声, 提高系统的长期稳定性. 相似文献
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采用外部F-P腔自锁定单模量子阱半导体激光器,观察到强度噪声的压缩现象,并同时大幅度降低了位相起伏.在35MHz附近观察到19.3%的强度压缩,对应激光输出的压缩度为37.8%,在9kHz-100MHz范围内观察到约3个数量级的位相噪声降低.获得了近最小测不准态.
关键词: 相似文献
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Y. Ben-Aryeh 《Physics letters. A》2011,375(10):1300-1303
The possibility of using squeezed states and balanced homodyne detection of optical signals in a Michelson interferometer is discussed. The present analysis describes photon statistics measurements effects related to quadrature balanced homodyne detection showing the advantage of using this scheme for detecting weak optical signals. 相似文献
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Performing homodyne detection at a single output port of a squeezed-state light interferometer and then separating the measurement quadrature into two intervals can realize super-resolving and super-sensitive phase measurements, which is equivalent to a binary-outcome measurement. Obviously, the single-port homodyne detection may lose almost part of the phase information, reducing the estimation precision. Here, we propose a data-processing technique over the double-port homodyne detection, where the two-dimensional measurement quadrature (p1, p2) has been divided into two regions. With such a binary-outcome measurement, we estimate the phase shift accumulated in the interferometer by inverting the output signal. By analyzing the full width at half maximum of the signal and the phase sensitivity, we show that both the resolution and the achievable sensitivity are better than that of the previous binary-outcome scheme. 相似文献
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R. Kumar E. BarriosA. MacRae E. CairnsE.H. Huntington A.I. Lvovsky 《Optics Communications》2012,285(24):5259-5267
We present a comprehensive theory and an easy to follow method for the design and construction of a wideband homodyne detector for time-domain quantum measurements. We show how one can evaluate the performance of a detector in a specific time-domain experiment based on the electronic spectral characteristic of that detector. We then present and characterize a high-performance detector constructed using inexpensive, commercially available components such as low-noise high-speed operational amplifiers and high-bandwidth photodiodes. Our detector shows linear behavior up to a level of over 13 dB clearance between shot noise and electronic noise, in the range from DC to 100 MHz. The detector can be used for measuring quantum optical field quadratures both in the continuous-wave and pulsed regimes with standard commercial mode-locked lasers. 相似文献
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Squeezed states belong to the most prominent non-classical resources. They have compelling applications in precise measurement, quantum computation, and detection. Here, we report on the direct measurement of 13.8 d B squeezed vacuum states by improving the interference efficiency and gain of balanced homodyne detection. By employing an auxiliary laser beam, the homodyne visibility is increased to 99.8%. The equivalent loss of the electronic noise is reduced to 0.05% by integrating a junction field-effect transistor(JFET) buffering input and another JFET bootstrap structure in the balanced homodyne detector. 相似文献
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We report a new all-optical noise free NAND logic operation using squeezed state of light with high speed of operation. The squeezed state of light generated by means of optical parametric amplification (OPA). The lights were generated in the same way to maintain the same characteristics. Balance homodyne detection scheme is utilized to detect the squeezed state of light. It is one of the promising squeezed light based devices for the next generation logic optical circuits. 相似文献
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本文仔细讨论了相位算子在单模压缩态光场中的行为,计算了压缩态下相位算子的平均值和涨落。在得到了严格的、普遍性的结果后我们详细地讨论了压缩真空态这一特殊情形下的结果。此外,本文还讨论了严格的结果在经典极限下的渐近行为。 相似文献
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利用量子技术增强Sagnac效应提高陀螺输出精度具有重要的研究意义, 是实现全自主导航的重要途径. 以相干态激光作为输入光源的光学陀螺因真空零点波动使其输出精度限制于散粒噪声极限而难以提高. 为减小真空波动的影响, 提出在激光输入的分束器的另一输入端输入压缩真空光并结合平衡零拍探测技术的方法增强Sagnac效应. 理论分析表明Sagnac效应性能得到有效提升: 干涉输出的灵敏度检测极限和动态范围均随着压缩程度的增加而呈指数级增长. 该方法只需对经典光学陀螺做少量改动就可实现, 是提高光学陀螺输出精度的一种新方法. 相似文献