A novel refractive index (RI) sensor based on a fiber Mach-Zehnder interferometer was realized by concatenating two single-mode tapers separated middle section. The proposed device had minimum insertion loss of 3 dB and maximum interferometric extinction ratio over 20 dB. resolution (0.171 nm) the two-taper to its surrounding RI change (0.01) found be comparable that (0.252 similar structures made from an identical long-period gratings pair, ease fabrication makes it low-cost alternative...

A simple refractive index sensor based on a Michelson interferometer in single-mode fiber is constructed and demonstrated. The consists of single symmetrically abrupt taper region short piece that terminated by ~500 nm thick gold coating. sensitivity the new similar to long-period-grating-type sensor, its ease fabrication offers low-cost alternative current sensing applications.

Mach-Zehnder and Michelson interferometers using core-offset attenuators were demonstrated.As the relative offset direction of two in interferometer can significantly affect extinction ratio interference pattern, single attenuator-based sensors appear more robust repeatable.A novel fiber refractive index (RI) sensor was subsequently realized by a attenuator layer 500-nm gold coating.The device had minimum insertion loss 0.01 dB maximum over 9 dB.The sensitivity (0.333 nm) new to its...

Using a large-angle refractometer, the refractive indices of water, methanol, acetonitrile, acetone, ethanol, formaldehyde solution, 2-propanol, hexanes, 1-propanol, 2-butanol, tetrahydrofuran, dichloromethane, 1,4-dioxane, cyclohexane, N,N-dimethylformamide, ethylene glycol, N,N-dimethylacetamide, chloroform, glycerol, trichloroethylene, dimethylsulfoxide, p-xylene, ethylbenzene, toluene, m-xylene, benzene, and o-xylene were measured at 1550 nm compared to literature values. In addition, 48...

Pulsed, visible and near-infrared laser light is coupled into an optical fiber, which wound a loop using fiber splice connector. The pulses traveling through the fiber-loop are detected photomultiplier detector. It found that once it experiences very little loss do large number of round trips before their intensity below detection threshold. Measurements loss-per-pass ring-down time allow for characterization different mechanisms in This method resembles “cavity absorption spectroscopy” well...

The thermal, oxidative and photochemical stability of the scintillator liquid proposed for SNO+ experiment has been tested experimentally using accelerated aging methods. constituents was determined through fluorescence excitation emission matrix (EEM) spectroscopy absorption spectroscopy, parallel factor analysis (PARAFAC) as an multivariate tool. By exposing to a well-known photon flux at 365 nm by measuring decay rate shifters formation their degradation products, we can place upper limit...

Compact interferometers based on waveguiding structures have found countless applications in refractive index measurements, chemical sensing, as well temperature and pressure measurements. The most common fiber devices are Mach–Zehnder interferometry Michelson interferometry—two design concepts that can readily be implemented using simple optic components, such mode splitters combiners, gratings, tapers, among others. Fiber also conducted the Sagnac effect Young (double-slit) interferometer....

Now you see it, now don't: A specially designed reactor that heats only a small area of Pd foil during Suzuki–Miyaura coupling permits observation the surface changes reaction. Dissolution occurs in heated zone, and presence aryl iodide, whereas deposition preferentially on unheated zones adjacent to reactive zone. SEM XPS are employed probe before after

The adiabatic ionization potentials of TiO, ZrO, NbO, and MoO have been measured using two-color photoionization efficiency (PIE) spectroscopy mass-analyzed threshold (MATI). From the sharp thresholds in PIE MATI spectra following were derived: IP(TiO)=6.8197(7) eV, IP(ZrO)=6.812(2) IP(NbO)=7.154(1) IP(MoO)=7.4504(5) eV. These values combined with metal atoms bond energies transition oxide cations, D0(MO+) [M. R. Sievers et al., J. Chem. Phys. 105, 6322 (1996)] to derive energies, D0(MO),...

Cavity ring-down spectroscopy has proven to be a very sensitive gas-phase spectroscopic technique, suitable record either weak transitions of abundant gases or stronger trace gases. Here, an adaptation the measurement principle optical waveguides is presented. Fiber-loop (FLRDS) allows for absorption spectra minute quantities liquid solutions. An fiber wound into loop using splice connector. A nanosecond laser light pulse (λ∼810 nm) coupled and pulses are detected photomultiplier detector....

Fiber-loop ring-down spectroscopy (FLRDS) is a recently developed absorption spectroscopic technique suitable for very small liquid samples. It based on measurements of the optical decay constant laser intensity in loop made waveguide material. This changes as samples containing absorbing species are introduced into loop. In this report, it demonstrated that one can also obtain using continuous wave beam modulated and then coupled an fiber The inherent exponential introduces phase shift...

We describe an in-fiber interferometer based on a gas-filled hollow-core photonic crystal fiber. Expressions for the sensitivity, figure of merit and refractive index resolution are derived, values experimentally measured theoretically validated using mode field calculations. The indices nine monoatomic molecular gases with δns < 10-6.

A chemical sensor based on a coated long-period grating has been prepared and characterized. Designer coatings polydimethylsiloxane were by the incorporation of diphenylsiloxane titanium cross-linker in order to provide enhanced sensitivity for variety key environmental pollutants optimal refractive index coating. Upon microextraction analyte into polymer matrix, an increase coating resulted change attenuation spectrum grating. The was interrogated using ring-down detection as means amplify...

We demonstrate a method for measuring optical loss simultaneously at multiple wavelengths with cavity ring-down spectroscopy (CRD). Phase-shift CRD is used to obtain the absorption of sample from phase lag intensity modulated light that entering and exiting an cavity. performed dual-wavelength detection by using two different laser sources frequency-division multiplexing. Each wavelength separate frequency, broadband detector records total signal. This signal then demodulated lock-in...

The first ionization potentials (${V}_{\mathrm{IP}}$'s) of copper, silver, and gold have been reassessed using a two-color resonant excitation scheme on laser-vaporized atomic beams Cu, Ag, Au. Rydberg levels the ${\mathrm{nd}}^{10}{n}_{R}{s}^{1}{(}^{2}{S}_{1/2})$ ${\mathrm{nd}}^{10}{n}_{R}{d}^{1}{(}^{2}{D}_{3/2,5/2})$ series converging to ground ${}^{1}S$ term singly charged cations were excited pulse-field ionized. fit yielded...

A low-noise transducer based on a fiber Fabry-Perot (FFP) cavity was used as pickup for an acoustic guitar.A distributed feedback (DFB) laser locked to 25 MHz-wide resonance of the FFP using Pound-Drever-Hall method.The correction signal audio output and preamplified sampled at up 96 kHz.The system is largely immune against optical noise sources, exhibits flat frequency response from infrasound region about kHz, has distortion-free range 50 dB.

Creating N-heterocyclic carbene and thiol micropatterns for electrochemical fabrication of copper micro-structures.