Yazar "Ozbay, Ekmel" için listeleme
-
94.8 Km-Range Direct Detection Fiber Optic Distributed Acoustic Sensor
Uyar, Faruk; Onat, Talha; Unal, Canberk; Unal, Canberk; Ozdur, Ibrahim; Ozbay, Ekmel (IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 01.01.2019)This work demonstrates an ultra-long range direct detection fiber optic distributed acoustic sensor which can detect vibrations at a distance of 94.8 km with 10 m resolution along the sensing fiber. (C) 2019 The Author(s) -
Coupling enhancement of split ring resonators on graphene
Cakmakyapan, Semih; Caglayan, Humeyra; Ozbay, Ekmel (PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND, 2014)Metallic split ring resonator (SRR) structures are used in nanophotonics applications in order to localize and enhance incident electromagnetic field. Electrically controllable sheet carrier concentration of graphene ... -
A Direct Detection Fiber Optic Distributed Acoustic Sensor With a Mean SNR of 7.3 dB at 102.7 km
Uyar, Faruk; Onat, Talha; Unal, Canberk; Kertelog, Tolga; Ozbay, Ekmel; Ozdur, Ibrahim (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA, 2019)In this work, we present the experimental results of a direct detection phi-OTDR based distributed acoustic sensor system. The system uses two cascaded acousto-optic modulators in order to generate optical pulses with very ... -
Enhanced transmission and beaming via a zero-index photonic crystal
Hajian, Hodjat; Ozbay, Ekmel; Caglayan, Humeyra (AMER INST PHYSICS, 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA, 2016)Certain types of photonic crystals with Dirac cones at the Gamma point of their band structure have a zero effective index of refraction at Dirac cone frequency. Here, by an appropriate design of the photonic structure, ... -
Enhanced tunability of V-shaped plasmonic structures using ionic liquid gating and graphene
Ozdemir, Onur; Aygar, A. Melis; Balci, Osman; Kocabas, Coskun; Caglayan, Humeyra; Ozbay, Ekmel (PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND, 2016)Graphene is a strong candidate for active optoelectronic devices because of its electrostatically tunable optical response. Current substrate back-gating methods are unable to sustain high fields through graphene unless a ... -
Experimental Analysis of Non-linear Phenomena due to Perturbation Amplitude in φ-OTDR Based Fiber Optic Distributed Vibration Sensor
Uyar, Faruk; Kartaloǧlu, Tolga; Ozbay, Ekmel; Ozdur, Ibrahim Tuna (Optica Publishing Group (formerly OSA), 2020)We experimentally analyze the non-linearity effect due to the perturbation amplitude in the φ-OTDR based fiber optic distributed vibration sensor by investigating the effects of large disturbance signal. -
Field Test and Fading Measurement of a Distributed Acoustic Sensor System over a 50 km-long Fiber
Uyar, Faruk; Kartaloglu, Tolga; Ozdur, Ibrahim; Ozbay, Ekmel (SPIE-INT SOC OPTICAL ENGINEERING, 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA, 2018)In this study, we present a direct detection distributed acoustic sensor based on phase-sensitive optical time domain reflectometer (phi-OTDR) with long sensing range and high signal-to-noise ratio (SNR), which is field-tested ... -
Guided Plasmon Modes of a Graphene-Coated Kerr Slab
Hajian, Hodjat; Rukhlenko, Ivan D.; Leung, Pui Tak; Caglayan, Humeyra; Ozbay, Ekmel (SPRINGER, 233 SPRING ST, NEW YORK, NY 10013 USA, 2016)We study analytically propagating surface plasmon modes of a Kerr slab sandwiched between two graphene layers. We show that some of the modes that propagate forward at low field intensities start propagating with negative ... -
The Investigation of Rayleigh Backscattered Signal Statistics in a phi-OTDR System Incorporating Optical Pre-Amplifier
Uyar, Faruk; Kartaloglu, Tolga; Ozbay, Ekmel; Ozdur, Ibrahim (IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 2020)We theoretically model and experimentally demonstrate the photon statistics of Rayleigh backscattered signal in a phi-OTDR based distributed fiber optical sensor in the presence of amplified spontaneous emission noise ... -
Multiple slow waves and relevant transverse transmission and confinement in chirped photonic crystals
Serebryannikov, Andriy E.; Cakmak, A. Ozgur; Colak, Evrim; Caglayan, Humeyra; Kurt, Hamza; Ozbay, Ekmel (OPTICAL SOC AMER, 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA, 2014)The dispersion properties of rod-type chirped photonic crystals (PhCs) and non-channeled transmission in the direction of the variation of structural parameters from one cell of such a PhC to another are studied. Two types ... -
A Simple Method for Enhancing the SNR in Direct Detection (p-OTDR based Distributed Acoustic Sensors
Uyar, Faruk; Kartaloglu, Tolga; Unal, Canberk; Ozbay, Ekmel; Ozdur, Ibrahim (IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 2020)A simple and effective method for increasing the SNR and range in fp-OTDR based direct -detection distributed acoustic sensors is proposed and experimentally verified. The proposed method results in 11 dB SNR improvement ...
