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Generation and detection of bright quantum entangled light pulses using adaptive optical pulse control in frequency domain

使用频域自适应光脉冲控制生成和检测明亮的量子纠缠光脉冲

基本信息

批准号：
14350191
负责人：
KANNARI Fumihiko
金额：
$ 9.6万
依托单位：
Keio University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14350191/
关键词：
femtosecond laser pulses photon-number squeezing quadrature phase squeezing quantum entanglement pulse shaping in frequency domain adaptive control optical fiber propagation balanced homodyne detection 光ファイバー伝搬最適制御

项目摘要

Quantum correlation is evolved via optical nonlinearities induced by ultrashort laser pulses in optical fibers. In this study, particular emphasis was placed on the quantum correlation formation among frequency modes of ultrashort laser pulses, and generation and detection of photon-number squeezing was experimentally and theoretically studied. The following results were obtained.(1)When an optical short pulse propagates an optical fiber in the anomalous dispersion regime, negative quantum correlation is formed among photon-number density around the center of spectrum. We have theoretically revealed that the negative quantum correlation, which directly corresponds to photon-number squeezing, can be dramatically improved when the spectral phase of the input laser pulse is adaptively shaped by referring to the negative correlation of the output pulse. Moreover, we can achieve two-mode squeezing among different spectral components in the laser pulse using the similar adaptive control sche … More me. However, these have not been realized in experiments yet because of spatiotemporal coupling effect at a spectral pulse shaping device, where some frequency components couple to the fiber with extremely low efficiency.(2)Ultra-broad spectrum is generated from a photonic crystal fiber via self-phase modulation, stimulated Raman scattering and four-wave mixing when an optical pulse of which center wavelength locates near the zero dispersion wavelength of the fiber is launched The Stokes Raman component propagates the fiber with spectral shift toward longer wavelength and exhibits soliton-like nature. We experimentally observed for the first time that extremely higher photon-number squeezing is obtainable at the Stokes Raman component, From our numerical analysis, complicated quantum correlation is formed in the broad spectrum. Higher photon-number squeezing is also obtainable at anti-Stokes component.(3)Since the anti-Stokes pulse propagates the fiber by being trapped by the Stokes pulses. Such co-propagation generates quantum correlation between two pulses. Using this mechanism, we revealed that quantum correlation can construct between two pulses with different center frequency when the two pulse can propagate together in a fiber. Therefore, the fiber could be a platform to manipulate quantum correlation among pulses.(4)We repeated the similar experiments with 1.5μm ultrashort pulses generated by an Er-fiber laser source. However, due to significant excess noise caused by ASE, photon-number squeezing cannot be attained. However, we succeeded to generate quadrature squeezing with vacuum state. Therefore, Er fiber sources are still useful to generate quantum entangled state with continuous variable. Less

量子相关性是通过光纤中超短激光脉冲引起的光学非线性而演变的。本研究特别关注超短激光脉冲频率模式之间的量子关联形成，并对光子数压缩的产生和检测进行了实验和理论研究。得到了以下结果：(1)当光短脉冲在反常色散区域的光纤中传播时，光谱中心周围的光子数密度之间形成负量子相关性。我们从理论上揭示，当输入激光脉冲的光谱相位通过参考输出脉冲的负相关性进行自适应整形时，直接对应于光子数压缩的负量子相关性可以得到显着改善。此外，我们可以使用类似的自适应控制方案实现激光脉冲中不同光谱分量之间的双模压缩。然而，由于光谱脉冲整形装置的时空耦合效应，一些频率分量耦合到光纤的效率极低，这些尚未在实验中实现。(2)当中心波长位于零色散波长附近的光脉冲时，光子晶体光纤通过自相位调制、受激拉曼散射和四波混频产生超宽光谱。推出光纤斯托克斯拉曼组件以光谱向更长波长移动的方式传播光纤，并表现出类似孤子的性质。我们通过实验首次观察到斯托克斯拉曼分量可以获得极高的光子数压缩，从我们的数值分析来看，在广谱范围内形成了复杂的量子相关性。在反斯托克斯分量处也可以获得更高的光子数压缩。(3)由于反斯托克斯脉冲通过被斯托克斯脉冲捕获而在光纤中传播。这种共同传播在两个脉冲之间产生量子相关性。利用这种机制，我们揭示了当两个脉冲可以在光纤中一起传播时，具有不同中心频率的两个脉冲之间可以构建量子相关性。因此，光纤可以成为操纵脉冲之间量子相关性的平台。(4)我们用铒光纤激光源产生的1.5μm超短脉冲重复了类似的实验。然而，由于 ASE 引起的显着过量噪声，无法实现光子数压缩。然而，我们成功地产生了真空态的正交压缩。因此，Er光纤源对于产生连续变量的量子纠缠态仍然有用。较少的