title: Terahertz polariton propagation in patterned materials.
abstract: Generation and control of pulsed terahertz-frequency radiation have received extensive attention, with applications in terahertz spectroscopy, imaging and ultrahigh-bandwidth electro-optic signal processing. Terahertz 'polaritonics', in which terahertz lattice waves called phonon-polaritons are generated, manipulated and visualized with femtosecond optical pulses, offers prospects for an integrated solid-state platform for terahertz signal generation and guidance. Here, we extend terahertz polaritonics methods to patterned structures. We demonstrate femtosecond laser fabrication of polaritonic waveguide structures in lithium tantalate and lithium niobate crystals, and illustrate polariton focusing into, and propagation within, the fabricated waveguide structures. We also demonstrate a 90 degrees turn within a structure consisting of two waveguides and a reflecting face, as well as a structure consisting of splitting and recombining elements that can be used as a terahertz Mach-Zehnder interferometer. The structures permit integrated terahertz signal generation, propagation through waveguide-based devices, and readout within a single solid-state platform.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Nikolay S
authors.initials: NS
authors.lastname: Stoyanov
authors.forename: David W
authors.initials: DW
authors.lastname: Ward
authors.forename: Thomas
authors.initials: T
authors.lastname: Feurer
authors.forename: Keith A
authors.initials: KA
authors.lastname: Nelson
mesh_terms: D003198:Computer Simulation; D003461:Crystallography / Q000295:instrumentation / Q000379:methods*; D055590:Electromagnetic Phenomena / Q000295:instrumentation*; D004583:Electrons; D004867:Equipment Design; D007368:Interferometry / Q000295:instrumentation / Q000379:methods; D007834:Lasers; D008094:Lithium / Q000737:chemistry*; D008420:Manufactured Materials; D008422:Materials Testing / Q000295:instrumentation / Q000379:methods*; D008872:Microwaves; D008962:Models, Theoretical; D036103:Nanotechnology / Q000379:methods; D009556:Niobium / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D012542:Scattering, Radiation; D012666:Semiconductors; D013635:Tantalum / Q000737:chemistry*
chemical_list: D010087:Oxides; C473347:lithium tantalate oxide; D009556:Niobium; C091692:lithium niobate; D013635:Tantalum; D008094:Lithium