Nonlinear Propagation of Ultrashort Pulses in Two-Dimensional Silicon Photonic Bandgap Crystals

超短脉冲在光子带隙晶体（PBSs）中的传播是未来光子电路的重要研究方向，有望成为电子微芯片的补充。特别令人感兴趣的是超短脉冲在pbc中的传播，其中强度相关的折射率补偿了色散，从而使脉冲保持其时间形状（孤子）。此外，对于脉冲的光开关，研究这些孤子的相互非线性相互作用是很重要的。为了获得更丰富的孤子种类，需要研究维度大于1的孤子，例如，至少是二维的孤子。我们的目标是实验研究超短脉冲在二维等离子体中的传播。利用硅，二维光子晶体将被制造出来。来自红外、同步泵浦光参量振荡器的强脉冲、超短脉冲（ps和fs）和波长可调脉冲将通过pbc聚焦，测量传输脉冲的光谱、时间形状和载波相位作为输入脉冲参数和传播方向的函数。这些结果将与理论模型进行比较，以了解潜在的物理现象，验证新孤子的存在，并寻求光与光之间切换的新方案。

The propagation of ultrashort pulses in photonic bandgap crystals (PBSs) is of high interest for future photonic circuits, which are expected to supplement electronic microchips. Of particular interest is the propagation of ultrashort pulses in PBCs, where the intensity-dependent refractive index compensates the dispersion, such that the pulse preserves its temporal shape (solitons). Further, for an optical switching of pulses it is important to study the mutual nonlinear interaction of such solitons. To get access to a much richer variety of solitons it is required to study PBCs with a dimension higher than one, e.g., PBCs which are at least two-dimensional. Our goal is the experimental investigation of ultrashort pulse propagation in two-dimensional PBCs. Using Si, two-dimensional photonic crystals will be manufactured. Intense, ultrashort (ps and fs), and wavelength tunable pulses from an infrared, synchronously pumped optical parametric oscillator, will be focused through the PBCs to measure the spectrum, temporal shape and carrier phase of the transmitted pulses as a function of the input pulse parameters and direction of propagation. The results will be compared with theoretical modelling to unterstand the unterlying physics, to verify the existence of new solitons, and to pursue new schemes for switching of light by light.