A fiber-optic Fabry-Pérot acoustic sensor with a <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">${\sim}{100}\hbox{-}{\rm nm}$</tex></formula> -thick multilayer graphene diaphragm is reported. Acoustic testing demonstrates pressure-induced deflection of 1100 nm/kPa and noise equivalent signal level xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\sim}{\rm 60}~\mu{\rm Pa}/{\rm...

The purpose of this study was to characterize the expression procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2), a membrane-bound homodimeric enzyme that specifically hydroxylates lysine in telopeptide procollagens, and assess clinical significance PLOD2 colorectal cancer (CRC). Our results show is highly expressed CRC tumor tissues cell lines, both at mRNA protein levels. Next, we found positively correlated with grade (P = 0.001), T stage N &lt; an advanced TNM 0.001). Knockdown...

Similar in principle to recent implementations of a lidar system at 355 nm [Opt. Lett. 25, 1231 (2000), Appl. Opt. 44, 6023 (2005)], an incoherent-detection Mie Doppler wind 1064 was developed and deployed 2005 Rev. 12, 409 (2005)] for measurements the low troposphere, taking advantage aerosol scattering signal enhancement. We present number improvements made original increase its robustness long-period operation. These include multimode fiber receiving reference signal, mode scrambler allow...

We have successfully fabricated a series of sampled fiber Bragg gratings with easily adjustable sampling periods and duty cycles using an 800 nm femtosecond laser point-by-point inscription. The thermal stability the was investigated isochronal annealing tests, which indicated that are capable maintaining high reflectivity at temperatures up to 1000°C for 8 h. This demonstrates potential developed use in multi-wavelength lasers variety temperature applications.

We demonstrated a temperature-insensitive hydrogen (H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) sensor based on polarization-maintaining photonic crystal fiber (PM-PCF). The sensing element is section of PM-PCF coated with Pd/Ag composite film and incorporated into single mode Sagnac loop interferometer. birefringence PMPCF modulated by H absorption that induces deformation the film, resulting in shift interference spectrum at...

Brillouin distributed optical fiber sensing system based on spontaneous scattering frequency shift measurement may measure temperature in the fiber, due to dependence of temperature. In this paper, nonlinear theoretical models spectrum BOTDR are analyzed. The model parameters optimized with Levenberg-Marquardt algorithm. By numerical calculation, it is indicated that pseudo-Voigt function can approach approximated Voigt profile well and quickly.

An Er-doped superfluorescent fibre source with enhanced mean-wavelength stability 2 ppm over the 0°C to 70°C range using chirped grating is demonstrated. The effects of temperature fibre, pump power, wavelength, state polarisation, and feedback power have been considered minimised corresponding techniques.

An embedded optical fiber pressure sensor was made by sandwiching a piece of polarization maintaining photonic crystal (PM-PCF) between two polymer foils. The excess birefringence induced the transverse applied in different directions with respect to birefringent axes PM-PCF numerically calculated and slow axis identified be most sensitive direction. experimental test carried out incorporating Sagnac interferometer; output interference fringes were found shift linearly peak wavelength...

An all-optical fiber photoacoustic gas sensor with double resonant signal enhancement is presented. The uses a fiber-tip graphene nano-mechanical resonator operating at one of its resonances as the acoustic detector and micro-acoustic tube, whose frequency matched to that resonator, PA cell. Compared single detection five-fold achieved. With 138-mW pump power 1-s lock-in time constant, noise equivalent concentration ~25-ppb C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML"...

We propose a precision and flexible measurement method for the beat length of birefringence optical fiber (BOF) with hybrid Sagnac interferometer formed single mode directional coupler BOFs. The error equation was obtained based on estimation theory it found that there is an optimum certain BOF under test. can be less than 0.001 mm 1 pm wavelength 0.1 precision. With high performance interrogator technology special designed method, setup built standard deviation 3.08 × 10−4 achieved 250...

We propose and demonstrate experimentally a low-noise closed-loop fiber optic gyroscope (FOG) driven by two broadband sources simultaneously. The basic characteristic of built-up super light source (SBLS) consisting superluminescent diodes (SLDs) with different wavelengths was designed analyzed. dispersion half-wave voltage multifunction integrated optical circuit (MIOC) investigated theoretically experimentally. tested results agree well the theoretical model confirm that customized MIOC...

We propose a fast digital envelope detector (DED) based on the generalized harmonic wavelet transform to improve performance of coherent heterodyne Brillouin optical time domain reflectometry. The proposed DED can obtain undistorted envelopes due zero phase-shift ideal bandpass filter (BPF) characteristics (GHW). Its average ability benefits from passband designing flexibility GHW, and its demodulation speed be accelerated by using algorithm that only analyses signals interest within GHW...

We propose a demodulated signal distribution theory for self-interfered distributed acoustic sensing system. The region of Rayleigh backscattering including the in fiber is investigated theoretically under different combinations both path difference and pulse width Additionally we determine optimal solution between to obtain maximum phase change per unit length. experimentally test this realize good pressure sensitivity −150 dB re rad/(μPam) frequency range from 200 Hz 1 kHz.

In this paper, a single-fiber Sagnac-like interferometer is proposed and experimentally demonstrated for detecting atomic spin precession in an magnetometer. The has reciprocal optical structure, which insensitive to environmental disturbances. fiber system more flexible implementation miniature magnetometers, potential application magnetoencephalography systems. sensitivity the bandwidth of are also discussed. thermal bending disturbances observed, whereas long-term stability analyzed...

Eigen frequency is a very important parameter in fiber optic gyroscope (FOG). To establish an accurate measurement of eigen frequency, we propose new method based on employing the square-wave, over-bias modulation with double frequency. We investigate proposed both experimentally and theoretically. Experimental results show accuracy better than ±5 Hz, which satisfies most FOGs. A theoretical model gives good explanation experimental results. The simple, low-cost, easy to implement. In...

Spin-exchange relaxation-free atomic spin gyroscope (SERF gyro) has ultrahigh theoretical sensitivity and is regarded as one of the most potential gyroscopes. To investigate its rotation response, a high linear precession detection module was developed firstly by modifying fiber reflective Sagnac interferometer for operating it in closed-loop mode. The SERF gyro based on K-Rb- <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</sup> Ne...

A quasi-distributed acoustic sensing (QDAS) scheme based on identical low-reflective fiber Bragg grating is proposed and analyzed theoretically experimentally. We realize the demodulation of different location frequency simultaneously by using imbalanced Michelson interferometer φ-OTDR Phase Generated Carrier technology with 600 gratings(FBGs) written on-line during drawing ordinary signal mode fibers in an equal separation 2 m. further obtain 1.4 dB response flatness at range 200 Hz–1500 Hz...

Distributed polarization cross coupling (PCC) along the polarization-maintaining fiber (PMF), obtained from an optical coherence domain polarimetry (OCDP) system, is analyzed. It found that measured PCC data at each measurement location sum of OCDP source function centered a series discrete points, which do not represent true information. An algorithm developed to extract "true" and strength extracted are no longer dependent. A model relate in PMF coil optic gyro (FOG) bias drift due...

The wavelength tuning characteristics of a widely tunable modulated grating Y-branch laser operating in large temperature range was investigated experimentally. linear fine-tuning realized by sweeping the phase region current, and fine lookup table created with high resolution less than 0.1 pm. We found experimentally that tuned has an excellent correspondence there are small intercepts among parallel lines different temperatures. Based on this special characteristic, online simple...