title: Terahertz waves emitted from an optical fiber.
abstract: We report a simple method of creating terahertz waves by applying the photo-Dember effect in a (100)-oriented InAs film coated onto the 45-degree wedged-end facet of an optical fiber. The terahertz waves are generated by infrared pulses guided through the optical fiber which is nearly in contact with a sample and then measured by a conventional photo-conductive antenna detector. Using this alignment-free terahertz source, we performed proof-of-principle experiments of terahertz time-domain spectroscopy and near-field terahertz microscopy. We obtained a bandwidth of 2 THz and 180-microm spatial resolution. Using this method, the THz imaging resolution is expected to be reduced to the size of the optical fiber core. Applications of this device can be extended to sub-wavelength terahertz spectroscopic imaging, miniaturized terahertz system design, and remote sensing.
authors.affiliation: Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, Korea.
authors.forename: Minwoo
authors.initials: M
authors.lastname: Yi
authors.forename: Kanghee
authors.initials: K
authors.lastname: Lee
authors.forename: Jongseok
authors.initials: J
authors.lastname: Lim
authors.forename: Youngbin
authors.initials: Y
authors.lastname: Hong
authors.forename: Young-Dahl
authors.initials: YD
authors.lastname: Jho
authors.forename: Jaewook
authors.initials: J
authors.lastname: Ahn
mesh_terms: D005336:Fiber Optic Technology / Q000295:instrumentation* / Q000379:methods*; D007259:Infrared Rays; D008904:Miniaturization / Q000295:instrumentation* / Q000379:methods*; D055100:Optical Fibers; D011827:Radiation