Highly Efficient Terahertz Spintronic Emitter Integrated with Optimized Photonic Crystal

Spintronic terahertz emitters are new to the terahertz source family. They are broad-spectrum and gapless unlike traditional sources involving semiconductors and nonlinear crystals. Moreover, they can emit intense electromagnetic fields strong enough for nonlinear terahertz application, but on the other hand, they can operate with low excitation pulse energy, which makes them quite versatile sources. Unfortunately, spintronic emitters suffer from low conversion efficiency. In this work, we present a spintronic emission enhancement by integrating the emitter with a designed photonic structure. We show experimental results accompanied by simulations demonstrating the efficiency improvement up to almost one order.