title: Few-photon all-optical modulation in a photonic band-gap fiber.
abstract: We demonstrate 25% all-optical modulation with <20 photons, i.e., a few attojoules of energy, using nondegenerate two-photon absorption in rubidium atoms confined to a hollow-core photonic band-gap fiber. An attenuation of up to 3 dB is induced on an optical field with a switching energy density of less than one photon per (λ(2)/2π). We show that the temporal response of the system is determined by the 5-ns transit time of the atoms across the optical mode of the fiber, which results in a modulation bandwidth up to 50 MHz.
authors.affiliation: School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Vivek
authors.initials: V
authors.lastname: Venkataraman
authors.forename: Kasturi
authors.initials: K
authors.lastname: Saha
authors.forename: Pablo
authors.initials: P
authors.lastname: Londero
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Gaeta
mesh_terms: D000042:Absorption; D004867:Equipment Design; D005336:Fiber Optic Technology; D055100:Optical Fibers; D017785:Photons; D012413:Rubidium / Q000737:chemistry
chemical_list: D012413:Rubidium