Now showing items 1-20 of 41

    • Absolute Absorption Cross-Section Measurement of a Submonolayer film on a silica microresonator 

      Barnes, Jack A.; Gagliardi, Gianluca; Loock, Hans-Peter (2016-02-24)
      Conventional absorption spectroscopy is not nearly sensitive enough for quantitative overtone measurements on submonolayer coatings. While cavity-enhanced absorption detection methods using microresonators have the potential ...
    • Absorption Detection Using Optical Waveguide Cavities 

      Loock, Hans-Peter; Barnes, Jack A.; Gagliardi, Gianluca; Runkai Li, Runkai; Oleschuk, Richard; Wächter, Helen (2016-03-18)
      Cavity ring-down spectroscopy is a spectroscopic method that uses a high quality optical cavity to amplify the optical loss due to the light absorption by a sample. In this presentation we highlight two applications of ...
    • Absorption Measurements in Liquid Core Waveguides Using Cavity 

      Bescherer, Klaus; Barnes, Jack A.; Loock, Hans-Peter (2016-03-07)
      Short liquid core waveguides (LCWs) were included into a fiber-loop cavity ring-down absorption spectrometer to reduce the detection limit over, both, single pass absorption in a LCW and cavityenhanced absorption using a ...
    • Absorption Measurements in Microfluidic Devices Using Ring-Down Spectroscopy 

      Trefiak, Nicholas R.; Barnes, Jack A.; Rask, Fiona; Courtney, Daniel G.; Walford, Richard; Li, Runkai; Oleschuk, Richard; Loock, Hans-Peter (2016-03-29)
      When monitoring separation events in microfluidic devices, one frequently needs to detect small amounts of analyte in picolitre sized volumes with a time response of milliseconds. Fluorescence detection is typically the ...
    • Assessment of the Oxidative Stability of Lubricant Oil using Fiber-Coupled Fluorescence Excitation–Emission Matrix Spectroscopy 

      Omrani, Hengameh; Dudelzak, Alexander E.; Hollebone, Bruce P.; Loock, Hans-Peter (2016-02-24)
      The fluorescence of antioxidant additives in lubricant oil was used as an indicator of oxidative stability of the oil. It was found that the decrease in fluorescence intensities of phenyl--napthylamine, its dimer, and ...
    • Cavity-Enhanced Photoacoustic Detection Using Acoustic and Fiber-Optic Resonators 

      MacLean, Amy G; Schneider, Leila Tamina; Freytag, Annica I.; Gribble, Adam; Barnes, Jack A.; Loock, Hans-Peter (2016-03-02)
      A wineglass has been used as an acoustic resonator to enhance the photoacoustic signal generated by laser excitation of absorbing dyes in solution. The amplitude of the acoustic signal was recorded using a fiber-optic ...
    • Chemical Sensing Using a Polymer Coated Long-Period Fiber Grating Interrogated by Ring-Down Spectroscopy 

      Barnes, Jack A.; Brown, Robert Stanley; Cheung, A.H.; Dreher, Marian; Mackey, G.; Loock, Hans-Peter (2016-03-15)
      An etched long-period grating was used as a refractive index sensor for vapours of four volatile organic compounds, i.e. m-xylene, cyclohexane, trichloroethylene and commercial gasoline. The sensitivity to the vapours was ...
    • Chemical Sensing Using Fiber Cavity Ring-Down Spectroscopy 

      Waechter, Helen; Litman, Jessica; Cheung, Adrienne H.; Barnes, Jack A.; Loock, Hans-Peter (2016-03-18)
      Waveguide-based cavity ring-down spectroscopy (CRD) can be used for quantitative measurements of chemical concentrations in small amounts of liquid, in gases or in films. The change in ring-down time can be correlated to ...
    • Chemical Sensor Based on a Long-Period Fibre Grating Modified by a Functionalized Polydimethylsiloxane Coating 

      Barnes, Jack A.; Dreher, Marian; Plett, Krista; Brown, R. Stephen; Crudden, M. Cathleen; Loock, Hans-Peter (2016-07-05)
      A chemical sensor based on a coated long-period grating has been prepared and characterized. Designer coatings based on polydimethylsiloxane were prepared by the incorporation of diphenylsiloxane and titanium cross-linker ...
    • Detection Limits of Chemical Sensors: Applications and Misapplications 

      Loock, Hans-Peter; Wentzell, Peter D. (2016-03-08)
      The limit of detection (LOD) and the sensitivity of a chemical sensor are defined using IUPAC guidelines. The LOD from simulated and experimental data is calculated from a calibration curve using a simple statistical model ...
    • Detection of Lead Contamination of Water and VOC Contamination of Air Using SOI Micro-Optical Devices 

      Saunders, J.; Dreher, Marian; Crudden, M. Cathleen; Du, J.; Loock, Hans-Peter; Xu, D.X; Densmore, A.; Ma, R.; Janz, S.; Vachon, M.; Lapointe, J.; Delâge, A.; Schmid, J.; Cheben, P. (2016-03-17)
      Micro-photonic SOI Mach-Zehnder interferometers were coated with solid-phase micro-extraction materials derived from polydimethylsiloxane to enable sensing of volatile organic compounds of the BTEX class in air. A different ...
    • Direct Sensing in Liquids Using Whispering-Gallery-Mode Droplet Resonators 

      Avino, Saverio; Krause, Anika; Zullo, Rosa; Giorgini, Antonio; Malara, Pietro; De Natale, Paolo; Loock, Hans-Peter; Gagliardi, Gianluca (2016-03-03)
      Liquid droplets suspended by the tip of a thin wire, a glass capillary, or a needle form high-Q optical resonators, thanks to surface tension. Under gravity equilibrium conditions, the maximum drop diameter is approximately ...
    • Enhanced Nanoparticle Detection with Liquid Droplet Resonators 

      Foreman, M.R.; Avino, Saverio; Zullo, Rosa; Loock, Hans-Peter; Vollmer, F.; Gagliardi, G. (2016-02-25)
      Whispering gallery mode particle sensing experiments are commonly performed with solid resonators, whereby the sensing volume is limited to the weak evanescent tail of the mode near the resonator surface. In this work we ...
    • Fabrication and Modeling of Multimode Fiber Lenses 

      Bescherer, Klaus; Munzke, Dorit; Oliver Reich, Oliver; Loock, Hans-Peter (2016-03-07)
      We report on the fabrication, modeling, and experimental verification of the emission of fiber lenses fabricated on multimode fibers in different media. Concave fiber lenses with a radius of 150 μm were fabricated onto a ...
    • A Fabry-Perot Refractometer for Chemical Vapor Sensing by Solid-Phase Microextraction 

      St-Gelais, R.; Mackey, G.; Saunders, J.; Zhou, J.; Leblanc-Hotte, A.; Poulin, A.; Barnes, Jack A.; Loock, Hans-Peter; Brown, Robert Stanley; Peter, Yves-Alain (2016-03-14)
      The contour lithography method [1] is used to improve the fabrication yield of previously demonstrated [2] microfluidic Fabry-Perot (FP) refractive index (RI) sensors. The sensors are then coated with polydimethylsiloxane ...
    • Fiber-Optic Ring-Down Spectroscopy Using a Tunable Picosecond Gain-Switched Diode Laser 

      Andachi, M.; Nakayama, T.; Kawasaki, M.; Kurokawa, S.; Loock, Hans-Peter (2016-03-23)
      Visible and near-infrared laser light pulses were coupled into two different types of optical fiber cavities. One cavity consisted of a short strand of fiber waveguide that contained two identical fiber Bragg gratings. ...
    • Fluorescence Excitation–Emission Matrix (EEM) Spectroscopy and Cavity Ring-Down (CRD) Absorption Spectroscopy of Oil-Contaminated Jet Fuel Using Fiber-Optic Probes 

      Omrani, Hengameh; Barnes, Jack A.; Dudelzak, Alexander E.; Loock, Hans-Peter; Waechtera, Helen (2016-03-11)
      Excitation emission matrix (EEM) and cavity ring-down (CRD) spectral signatures have been used to detect and quantitatively assess contamination of jet fuels with aero-turbine lubricating oil. The EEM spectrometer has been ...
    • Gas Sensing Using Polymer-Functionalized Deformable Fabry–Perot Interferometers 

      St-Gelais, Raphael; Peter, Yves-Alain; Mackey, Gillian; Saunders, John; Zhou, Jingjing; Leblanc-Hotte, Antoine; Poulin, Alexandre; Barnes, Jack A.; Loock, Hans-Peter; Brown, R. Stephen (2016-03-03)
      We report a chemical vapor sensor in which polymer swelling, upon analyte absorption, is used to deform an on-chip silicon Fabry–Perot interferometer (FPI). The magnitude of the deformation, recorded through the resonance ...
    • Long-Period Gratings in Chemical Sensing 

      Barnes, Jack A.; Brown, R. Stephen; Cipot-Wechsler, Judy; Crudden, M. Cathleen; Du, Jenny; Loock, Hans-Peter; Plett, Krista (2016-03-21)
      A chemical sensor system consisting of a coated long period grating, which was spliced into a fiber loop cavity, has been prepared and characterized. Designer coatings based on polydimethylsiloxane and nanostructured ...
    • Loss Determination in Microsphere Resonators by Phase-Shift Cavity Ring-Down Measurements 

      Barnes, Jack A.; Carver, B.; Fraser, James M.; Gagliardi, G.; Loock, Hans-Peter; Tian, Zhaobing; Wilson, M.W.B.; Yam, Scott S.-H.; Yastrubshak, O. (2016-03-21)
      The optical loss of whispering gallery modes of resonantly excited microresonator spheres is determined by optical lifetime measurements. The phase-shift cavity ring-down technique is used to extract ring-down times and ...