A high-resolution and large-dynamic-range temperature sensor adopting a pair of fiber Bragg grating as Fabry–Pérot cavity (FBG-FP) laser frequency dither locking method is proposed experimentally demonstrated. This exhibits resolution 7×10 −4 °C dynamic range ∼46 °C. It especially useful for applications where very small changes need to be detected, such deep ocean measurement.

A high-resolution and wide-range pressure sensor based on π phase-shifted fiber Bragg grating (π-FBG) encapsulated with metal thin-walled cylinder is reported. The has been tested a wavelength-sweeping distributed feedback laser, photodetector H 13 C 14 N gas cell. To perceive temperature synchronously, pair of π-FBGs are glued the outer wall along circumferential direction different angles. interference effectively corrected by high-precision calibration algorithm. reported sensitivity 4.42...

Ocean salinity plays an important role in oceanographic research as one of the fundamental parameters. An optical salinometer based on Michelson interferometer (MI) suitable for situ measurement deep-sea environments is proposed this work, and it features real-time calibration multichannel multiplexing using frequency modulated continuous wave (FMCW) technique. The symmetrical sapphire structure used to withstand pressure can not only achieve automatic temperature compensation, but also...

A novel electro-optic modulator based on graphene silicon (GoS) dual-slot waveguide is proposed, utilizing the electro-absorption and electro-refraction effect of graphene. The optical mode in can interact strongly with upper layer due to enhancement light intensity poor confinement nanometer slot. real part imaginary effective modal index relate propagation phase attenuation, respectively. Electro-absorption modulators be realized by reasonably tuning chemical potential through an applied...

Abstract A waveguide coupled surface plasmon sensor for detection of liquid with high refractive index (RI) is designed based on polymer materials. The effects variation the thickness Au film, polymethyl methacrylate (PMMA) buffer, and layer sensing performance are comprehensively investigated by using finite difference method. Numerical simulations show that a thinner gold film gives rise to more sensitive structure, while PMMA buffer has little effect sensitivity. For RI, sensitivity...

Compact high-performance electro-optic (EO) modulators are key elements for optical communications. An electro-absorption modulator is theoretically designed. Due to the introduction of graphene film over silicon slot waveguide, modulation efficiency strongly improved. The effect waveguide dimensions, dielectric insulator thickness, and carrier mobility on performances proposed EO have been comprehensively investigated. For 120-μm-long graphene-on-silicon modulator, extinction ratio 28 dB...

Wideband and polarization-insensitive operation are key issues for electro-optic modulators. An electro-absorption modulator based on graphene-silicon nitride hybrid waveguide has been proposed. Geometric parameters investigated through finite element method to enhance the interaction between optical mode graphene. For a 200-μm-long waveguide, modulation depth (MD) of 20 dB can be obtained when Femi level varies from 0.2 0.6 eV. The MD difference transversal electric polarization magnetic...

This letter proposes a long-period grating based on coupling between the long-range surface plasmon mode and cladding of thin Au film stripe fully buried in polymer SU-8. Periodical corrugation accompanied refractive index variation SU-8 upper-cladding were induced by ultraviolet-written technique. configuration along gives rise to observation strong resonance 3-mm long periodic grating. A rejection band with contrast -23.5 dB at wavelength 1561 nm was achieved, which can be tuned ~30...

Visible light variable optical attenuators (VOA) are essential devices in the application of channel power regulation and equalization wavelength-division multiplexing cross-connect nodes plastic fiber (POF) transmission systems. In this paper, a polymer/silica hybrid waveguide thermo–optic attenuator based on multimode interference (MMI) coupler is designed fabricated to operate at 650 nm. The single-mode condition, MMI coupler, transition taper dimensions optimized through beam propagation...

Abstract A metal-clad planar polymer waveguide refractive index sensor based on epoxy (EPO) materials by using light intensity interrogation at 850 nm is designed. The polymethyl methacrylate (PMMA) material deployed as the low (RI) buffer layer in order to better couple optical guided mode and surface plasmon polaritons (SPP) for working water environment. effects of gold film thickness, PMMA width, length sensing characteristics have been comprehensively studied. Simulation results...

A real-time seawater temperature measurement system based on a wavelength swept distributed feedback (DFB) laser is developed. The <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pi $ </tex-math></inline-formula> phase-shifted fiber Bragg grating ( -FBG) with narrow bandwidth of 12 pm used as the sensing probe. by linearly and periodically modulating driving current sawtooth wave signal. absorption line...

A thermo-optic waveguide mode switch based on an asymmetric Mach-Zehnder interferometer (MZI) is demonstrated. metal heater deposited one arm of the MZI to implement switching between LP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">01</sub> and xmlns:xlink="http://www.w3.org/1999/xlink">11a</sub> modes. The polymer/SiO xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> hybrid structure adopted decrease power consumption time. fabricated...

Optical loss induced by the arbitrary structure discontinuity in Au stripe that supports long-range surface plasmon-polaritons (LRSPPs) propagation is investigated this paper. A broad range of gap sizes, 4 to 20 μm, reported for 25 nm thick with different widths embedded 5 μm optically symmetric polymer SU-8. The simulations and experimental data find a high tunneling efficiency mode power transmission larger than 50% over 10 at wavelength 1550 nm. Accordingly, thermally activated in-line...

We present a high-resolution and large dynamic range <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pi $ </tex-math></inline-formula> -phase-shifted fiber Bragg grating ( -PSFBG) temperature sensor. A current modulated laser diode with linearized optical frequency sweep is used to interrogate the The sensor comprised of -PSFBG sensing head an HCN gas cell. cell functions as absolute reference compensate...

Electro–optic modulator is a key component for on-chip optical signal processing. An electro–optic phase based on multilayer graphene embedded in silicon nitride waveguide demonstrated to fulfill low-power operation. Finite element method adopted investigate the interaction enhancement between flake and mode. The impact of performance studied comprehensively. Simulation results show that modulation efficiency improves with increment layer number, as well length. 3-dB bandwidth around 48 GHz...

An optical waveguide displacement sensor according to core-cladding modes interference is theoretically proposed and experimentally demonstrated. Ultraviolet sensitive SU-8 polymer on silica used as the guiding layer. It covered by a 12 nm thick planar gold grating. The air gap sensing head which consists of end single-mode fiber facet can realize detection monitoring wavelength dip shifting in transmission spectra. Cladding propagating exposed be effectively excited end-fire coupling...

The interference between the long range surface plasmon (LRSP) mode and cladding in a gold stripe waveguide is theoretically investigated experimentally demonstrated. Epoxy polymer SU-8 used as dielectric cladding. Long period relief gratings are formed on top by ultraviolet light bleaching. mode, which excited due to field mismatch LRSP lead-in fiber interferes with guiding supported waveguide. A sinusoidal pattern contrast ratio of over 12 dB observed. Because diffraction introduced at...