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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

量子关联是通过超短激光脉冲在光纤中引起的光学非线性演化而来的。本论文重点研究了超短激光脉冲频率模式间量子关联的形成，并对光子数压缩的产生和检测进行了实验和理论研究。获得了以下结果。（1）当光脉冲在反常色散区的光纤中传播时，在光谱中心附近的光子数密度之间形成负量子关联。我们从理论上揭示了，负量子相关，这直接对应于光子数压缩，可以显着改善时，输入激光脉冲的光谱相位的自适应成形，通过参考输出脉冲的负相关。此外，利用类似的自适应控制策略，我们还可以实现激光脉冲中不同光谱分量之间的双模压缩 ...更多信息然而，由于光谱脉冲成形装置处的时空耦合效应，这些还没有在实验中实现，其中一些频率分量以极低的效率耦合到光纤。（2）当中心波长位于光子晶体光纤零色散波长附近的光脉冲通过自相位调制、受激拉曼散射和四波混频产生超宽光谱，斯托克斯拉曼分量在光纤中传播，光谱向长波方向移动，表现出类孤子性质。我们首次在实验上观察到在斯托克斯拉曼分量处可获得极高的光子数压缩。数值分析表明，在宽谱范围内形成了复杂的量子关联。在反斯托克斯分量处也可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。利用这种机制，我们揭示了当两个中心频率不同的脉冲在光纤中一起传播时，两个脉冲之间可以建立量子相关。因此，光纤可以作为一个平台来操纵脉冲之间的量子关联。(4)We用铒光纤激光器产生的1.5μm超短脉冲重复了类似的实验。然而，由于ASE引起的显著的过量噪声，光子数压缩不能实现。然而，我们成功地利用真空态产生了正交压缩。因此，Er光纤光源仍然可以用来产生连续变量的量子纠缠态。少