Magnetically driven Terahertz spectral filters and their applications

如今，非线性光学领域令人印象深刻的创新为实现新的可靠太赫兹（THz）源和探测器铺平了道路，直到最近，才完全运行的设备。这个合作研发项目的目的是与我们的两个工业合作伙伴Novacam Technologies Inc.和QPS Photronics Inc.，是为了证明一系列用于操纵太赫兹波的新型器件的可行性和有效性。特别是，我们建议证明磁驱动的可调谐光谱滤波器在太赫兹频率范围内。这种设备将依赖于PI先前演示的双线THz波导。主要思想是将布拉格光栅（BG）直接写入到我们的波导的金属结构上，从而充当凹口（即，抑制）滤波器。为了进一步调整这种滤波器的中心频率和线宽，我们将建议将我们的设备与一类特殊的磁性材料相结合，称为铁磁流体，其在太赫兹范围内大多是透明的。磁流体具有在外部静磁场偏置时改变其折射率的性质。通过将这种材料嵌入BG的结构中，我们将最终实现其光谱响应可以实时修改的滤波器（即，动态地），根据所施加的外部磁场，从而允许THz脉冲带宽的低损耗整形。我们相信，我们打算在该项目中开发的紧凑且经济实惠的动态调谐太赫兹光谱滤波器将在即将到来的太赫兹成像和下一代高速无线通信领域中发挥关键作用，这将包括建筑物内外的高速宽带无线数据传输。此外，这些设备已经引起了我们的工业合作伙伴的极大兴趣，他们打算通过提供用于操纵THz辐射的领先产品来显着增加他们在不断增长的THz市场上的存在。该项目的成果将使加拿大能够增加其在不断增长的ICT市场中的全球份额，尤其是在新兴的成像和信号处理领域。

Nowadays, impressive innovations in the field of nonlinear optics have paved the way for the realization of new reliable Terahertz (THz) sources and detectors and, only recently, fully operating devices. The aim of this collaborative Research and Development project, proposed in collaboration with our two industrial partners Novacam Technologies Inc. and QPS Photronics Inc., is to demonstrate the feasibility and effectiveness of a series of novel devices engineered for the manipulation of THz waves. In particular, we propose to demonstrate a magnetically driven tunable spectral filter in the THz frequency range. Such a device will rely on the two-wire THz waveguide previously demonstrated by the PI. The main idea is to directly write a Bragg grating (BG) onto the metallic structure of our waveguide, thus acting as notch (i.e., rejection) filter for the broadband THz propagating pulse. With the aim of further tuning the central frequency and the linewidth of such a filter we will propose to combine our device with a particular class of magnetic materials, named Ferrofluids, which are mostly transparent in the THz range. Ferrofluids have the property to change their refractive index when biased by an external static magnetic field. By embedding such materials in the structure of the BG, we will finally achieve a filter whose spectral response can be modified in real-time (i.e., dynamically), in function of the applied external magnetic fields, thus allowing a low loss reshaping of the THz pulse bandwidth. We believe that the compact and affordable dynamically tuned THz spectral filters we intend to develop in this project will play a key role in the forthcoming fields of THz imaging and next-generation high-speed wireless communications, which will consist of high speed broadband wireless data transfer within and outside buildings on short distances. Furthermore, such devices have already created a significant interest for our industrial partners who intend to significantly increase their presence on the growing THz market, by providing leading-edge products for the manipulation of THz radiation. The project results will allow Canada to increase its global share of the growing ICT market, above all in the burgeoning areas of imaging and signal processing.