Fourier optics and light stopping with nonlinear fronts

傅里叶光学和非线性前沿光停止

• 批准号: 493328928
• 负责人: Dr. Alexander Petrov
• 金额: --
• 依托单位: Institut für Optische und Elektronische Materialien E-12
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/493328928?language=en
• 关键词: Fourier; optics; light; stopping; nonlinear

In this proposal we draft the route towards experimental realisation of different index front-induced optical transitions close to the band edge of a periodical waveguides. Namely, light stopping, time lens, and ultrafast arbitrary waveform generation are considered. For that we propose to utilise silicon waveguides with Bragg gratings and operate them close to the band edge. The moving refractive index front will be generated in the same waveguide via instantaneous Kerr effect from the copropagating switching/pump pulse. To avoid the losses via free carrier generation we plan to use mid-infrared (MIR) radiation for the pump pulse.The proposed effects are utilising the theoretical concepts developed by our group in recent year which we now plan to demonstrate experimentally. In case of light stopping, like in a mechanical collision, the light pulse hits a propagating front and stops. Here, the light energy can be transferred to the zero group velocity mode and later released by a second front with an opposite slope. In case of a so-called optical push broom, the signal pulse is trapped by the index front with a simultaneous frequency change and compression. As we have recently shown theoretically the trapping in the front is equivalent to Fourier optics observed at the focal plane of conventional lenses. This effect allows not only pulse compression but also the transfer of information from real to reciprocal space and vice versa. Thus, a defined spectral composition of the signal can be converted in a designed short temporal pulse, allowing for customizable wave form generation.The proposed system will provide signal temporal compression, light stopping, and pulse structuring in integrated optics technology. The extension to the MIR pump pulse allows utilisation of established silicon waveguide technology with large nonlinearity and strong field confinement.

在本提案中，我们草拟了实验实现周期波导带边缘附近不同折射率前致光跃迁的路线。即，光停止，时间透镜和超快任意波形的产生被考虑。为此，我们建议利用硅波导与布拉格光栅，并操作他们接近带边缘。在同一波导中，共传播的开关/泵浦脉冲通过瞬时克尔效应产生移动折射率前沿。为了避免自由载流子产生带来的损耗，我们计划使用中红外（MIR）辐射作为泵浦脉冲。提出的效应是利用我们小组近年来发展的理论概念，我们现在计划通过实验来证明。在光停止的情况下，就像在机械碰撞中一样，光脉冲击中传播前沿并停止。在这里，光能可以转移到零群速度模式，然后由另一个斜率相反的锋面释放。在所谓的光推扫帚的情况下，信号脉冲被折射率前沿捕获，同时发生频率变化和压缩。正如我们最近在理论上所展示的，前面的捕获相当于在传统透镜焦平面上观察到的傅立叶光学。这种效应不仅允许脉冲压缩，而且允许信息从实空间传输到倒空间，反之亦然。因此，可以在设计的短时间脉冲中转换信号的定义频谱组成，从而允许可定制的波形生成。该系统将在集成光学技术中提供信号时间压缩、光停止和脉冲结构。MIR泵浦脉冲的扩展允许利用具有大非线性和强场约束的硅波导技术。