Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécom, Montréal, Quebec, Canada.
Opt Lett. 2013 May 1;38(9):1419-21. doi: 10.1364/OL.38.001419.
We experimentally demonstrate a superluminal space-to-time mapping process in grating-assisted (GA) codirectional coupling devices, particularly fiber long period gratings (LPGs). Through this process, the grating complex (amplitude and phase) apodization profile is directly mapped into the device's temporal impulse response. In contrast to GA counterdirectional couplers, e.g., Bragg gratings, this mapping occurs with a space-to-time scaling factor that is much higher than the propagation speed of light in vacuum. This phenomenon has been used for synthesizing customized complex optical pulse data sequences with femtosecond features (3.5 Tbit/s data rate) using readily feasible fiber LPG designs, e.g., with subcentimeter resolutions.
我们在光栅辅助（GA）同向耦合器件中实验演示了一种超光速的时空映射过程，特别是光纤长周期光栅（LPG）。通过这个过程，光栅的复（振幅和相位）变迹轮廓被直接映射到器件的时域脉冲响应中。与 GA 反向耦合器（例如布拉格光栅）不同，这种映射的空间-时间缩放因子远高于真空中光的传播速度。这种现象已经被用于使用现成的光纤 LPG 设计（例如，亚厘米分辨率）合成具有飞秒特征（3.5 Tbit/s 数据速率）的定制复杂光脉冲数据序列。
