We propose and demonstrate a 0.5 mm resolution distributed fiber temperature strain sensor with position-deviation compensation based on the Optical Frequency Domain Reflectometry. The helps maintain cross-correlation of Rayleigh spectra, which degenerates at higher resolution. Experimental results reveal strained segment recognized end 25 m fiber, 50,000 equivalent measuring points. repeatability ± 0.9 °C (12.5 pm) is obtained from 50 to 500 an 18 gold-coated accuracy 15 µɛ also achieved...

Geosynchronous Earth orbit (GEO) satellites can extend the transmission distance of quantum states and intercrossing time between ground, which will greatly promote application spatial scale communications. In this work we report first experimental test photonic polarization from a GEO SJ-20 satellite at more than 36,000 km to Li-jiang ground station Yun-nan Observatory. The equipment carried on send four kinds 50 MHz pulse frequency. A 1.76 m telescope related optical system in are used...

We demonstrate 10 kW spectral beam combination of six narrow-linewidth fiber amplifiers by two transmission gratings with a combining efficiency about 90%. The wavelengths incident beams range from 1056 to 1088 nm. Each amplifier delivers 2 output power laser 0.25 nm root-mean-square (RMS) linewidth. A dual-grating beam-combining system is constructed combine the into level high-power and control quality factor ${{\rm M}^2} \lt {2}$M2<2 dispersion compensation. To best our knowledge, this...

To give full play to the advantages of self-coherent systems in data center scene, problem random walk polarization state delivered local oscillator must be solved. An adaptive controller (APC) is an effective solution, with characteristics easy integration, low complexity, being reset-free, and so on. In this work, we experimentally demonstrated endlessly APC based on a Mach-Zehnder interferometer silicon-photonic integrated circuit. The thermally tuned only two control electrodes. It...

Digital radio-over-fibre transmission has been studied extensively as a way of providing seamless last-mile wireless connectivity by carrying digitised radio frequency (RF) services over broadband optical infrastructures. With the growing demand on capacity and number services, key challenge is enormous scale digital data generated after digitisation process. In turn, this leads to links needing have very large hence, high capital expenditure (CAPEX). paper, we firstly present then...

A miniature wide-range three-axis vector atomic magnetometer under spin-exchange relaxation-free regime has been developed. With a cylindrical vapor cell of size 10 mm in diameter and length, we have constructed single-beam configuration through polarization-maintaining fiber carrying the laser beam to sensor multimode guiding transmitted light field photodiode. rotating on plane perpendicular direction propagation another modulation pump direction, which are generated programmable gate...

We propose and demonstrate an integrated polarization sensing technique by fully exploiting the adaptive controller (APC) in a self-homodyne coherent (SHC) communication system. By analyzing APC control signal, input state of (SOP) can be restored. The effect tracking results on accuracy is carefully studied simulation to determine acceptable SOP rotation speed. experimentally restore trajectory using APC, conduct comparison with analysis instrument, verify its potential as measurement....

We present a novel hybrid electro-optic current transformer based on fast variable optical attenuator (FVOA) with the features of ultra-low power consumption and polarization insensitivity. An optic-electro feedback loop PID control algorithm is designed to compensate nonlinearity FVOA. In addition, impacts drift source variance fiber loss have been investigated eliminated. The built verified 0.85 mW. Experiments were made in which linearity, robustness, accuracy temperature stability...

This article describes a closed-loop detection MEMS accelerometer for acceleration measurement. paper analyzes the working principle of accelerometers in detail and explains relationship between zero bias, scale factor voltage reference. Therefore, combined compensation method is designed via reference source terminal temperature accelerometer, which comprehensively improves performance over wide range accelerometer. The experiment results show that initial reduced from 3679 ppm to 221 with...

We demonstrated a new optical fiber modal interferometer (MI) for airflow sensing; the novelty of proposed structure is that an MI fabricated based on piece HAF, which makes sensitive itself also hotwire. The made by applying arc-discharge tapering and then flame 10 mm length high attenuation (HAF, 2 dB/cm) with both ends spliced to normal single mode fiber. When diameter in processing region reduced about μm, near-infrared dispersion turning point (DTP) can be observed interferometer's...

Lack of suitable towed array has existed as a main problem for further extended use small underwater mobile platforms such UUV. In this paper, an ultra-thin fiber-optic hydrophone is developed based on DFB fiber laser, which diameter only 12mm. And the performance tested by towboat. The experimental results show that noise 69dB re. uPa/√Hz@1kHz. addition, can precisely determine spatial characteristics acoustic field at 6 knots, verifies feasibility laser in UUV and other platforms.

To improve the radiation resistance of Yb-doped fiber lasers, we investigate influence pre-radiation and photo-bleaching on gamma-radiated laser’s performance. When gamma dose is within 10 krad(Si) with a rate less than 0.4 rad(Si)/s, compared to output power non-pre-radiated laser, technique could enhance against gamma-ray. However, mode instability threshold was decreased, which caused by cumulated radiation-induced attenuation radiation. Based an electronic probe micro-analyzer, active...

Most pregnant epilepsy patients need to continue using anti-seizure medications (ASMs) control epileptic seizures.This study aimed evaluate the risk of early abortion in exposed monotherapy.We prospectively followed up treated with monotherapy our center between January 2010 and 2020 under real-world conditions. Early (spontaneous first trimester pregnancy) was endpoint.Of 211 pregnancies monotherapy, including 40% (n = 85) lamotrigine (LTG), 28% 58) oxcarbazepine (OXC), 15% 32) sodium...

A zero drift suppression method of a distributed feedback (DFB) fiber laser hydrophone is studied. The working principle the DFB and cause, phenomenon, influence are briefly introduced. design idea implementation described in detail. differential cross-multiplication demodulation improved by adding closed-loop control to appropriate stage, problem solved without any hardware modification. Simulation analysis experiments performed verify feasibility effectiveness method. experimental results...

We propose and experimentally demonstrate a two-stage digital differential method for atomic spin precession detection. The first operation is carried out with polarimeter module subsequent differential. second achieved by orthogonally modulating the polarization direction of linearly polarized probe light LiNbO 3 electro-optic modulation digitally demodulating difference in outputs corresponding to positive negative half periods square-waves. This insensitive error modulator double...

This paper describes a model that seeks to simultaneously optimize the location of multiple-server, congestible facilities in order realize company's maximal total captured demand. The effective demand at each customer node is elastic travel cost facility, and congestion facility. We propose greedy heuristic for resulting problem formulation, provide computational experiment.

Lithium niobate (LiNbO3) has become popular with applications in electronics and communication industries due to its excellent electro-optical nonlinear properties. This paper presents the influence of laser power, repetition frequency, number subpulses, depth each pass, scanning velocity picosecond dicing on multiple characteristics LiNbO3 using Taguchi method. By means analysis variance relations between characteristics, optimal ps-laser-dicing parameter is obtained good quality high...

With the development of fast digitiser and digital signal processing techniques, wide-band radio-over-fiber (DRoF) based wireless fronthaul systems have been extensively studied as a way offering multi-service coverage. data compression, high rate caused by digitisation can be reduced so to minimise infrastructure cost for last-mile cellular However, compression always comes with lower input power dynamic range. To overcome issue, this paper proposes novel fast-settling two-stage automatic...

This paper presents a novel method for the performance of an all-silicon accelerometer by adjusting ratio Si-SiO2 bonding area, and Au-Si area in anchor zone, with aim eliminating stress region. The study includes development model simulation analysis which demonstrates maps under different anchor-area ratios, have strong impact on accelerometer. In practical applications, deformation comb structure fixed zone is influenced region, causing distorted nonlinear response signal. results...