We experimentally demonstrate transverse load and strain sensing based on a fiber optic Fabry-Perot interferometer (FPI) with special air cavity, which was created by fusion splicing single mode (SMF), hollow core (HCF) several electrical arc discharges. The cavity height of this structure is higher than the cladding diameter SMF so that it can sense high sensitivity. sensitivity FPI sensor 1.31 nm∕N about 5 times more sensitive compared to current tip (0.2526 nm∕N). Meanwhile, also measure...

We report a novel fiber-optic hybrid-structured Fabry-Perot interferometer (HSFPI) based on large lateral offset splicing for simultaneous measurement of strain and temperature with advantages high sensitivity, low cost, easy fabrication. The high-strain sensitivity 28.95 pm/με low-temperature 0.54 pm/°C are obtained air cavity, is over five times compared to the current HSFPI (5.18 pm/με). In addition, sensitivities silica cavity are, respectively, 1.59 12.71 pm/°C. Thus, due different...

An ultra-short high-temperature fiber-optic sensor based on a silicon-microcap created by single-mode fiber (SMF) and simple fusion splicing technology is proposed experimentally demonstrated. A section of the SMF with at one end connected to “ peanut ” structure build microcap-based optical improved Michelson interferometer (MI). The optimal discharge parameters microcap length has been investigated achieve best extinction ratio 6.61 dB. size this MI 560 µm about 18 times shorter compared...

The parallel structured fiber-optic Fabry-Perot interferometer (FPI) is theoretically proposed and experimentally demonstrated for transverse load measurement based on Vernier-effect. This kind of sensor consists a hollow microsphere cavity FPI sensing function an air reference, both which are connected by 3 dB optical fiber coupler with the functionality Experimental results indicate that can provide high sensitivity -3.75 nm/N, 3.4 times higher than single FPI. Moreover, excellent features...

We propose a Metal–Insulator–Metal structure consists of two surface plasmon polaritons (SPPs) and an H-shaped resonator. The reflectance spectrum is numerically simulated by the two-dimensional finite-difference time-domain method. results show that this can act as pressure sensor. To our knowledge, first proposal to utilize SPP resonator form size be small few hundred nanometers. nano-scale sensor opens wide field for potential applications in biological biomedical engineering.

We experimentally demonstrated a novel fiber-optic hybrid structured Fabry-Perot interferometer with special air-cavity for simultaneous measurement of transverse load and temperature. By the linear phase finite impulse response filters, sensitivities silica-cavity are 1272.71 pm/N -53.07 pm/N, respectively, temperature 1.1 pm/°C 14 pm/°C. Thus, different to indicate that such structure can be used simultaneously measure

We investigate the impact of granular particles at bottom container, which is vibrating harmonically in vertical direction. Experiments demonstrate that strength, controlled by normalized vibration acceleration, undergoes a series subharmonic bifurcations, sequence period-doubling, period-quadrupling, chaos, period-tripling, period-sextupling, period-octupling, and so on. It observed accompanying bifurcations there always exists condensed state lower part bed. By using completely inelastic...

The photonic crystal fiber has received the widespread attention in sensing field because of its flexible structure and unique features. A refractive index temperature sensor based on D-shaped is designed analyzed. In side section fiber, a coat with gold film used as surface plasmon resonance (SPR) channel for measuring liquid determinand. Temperature sensitive liquid-toluene filled an air hole directional coupling to realize measurement. When SPR mode guided satisfy phase matching...

A diode-end-pumped tunable twisted-mode cavity Tm, Ho:YAG laser with single-longitudinal-mode (SLM) operation is demonstrated in this Letter. The maximal SLM output power 106 mW a slope efficiency of 4.86%. wavelength can be changed from 2090.38 to 2097.32 nm by tuning the angle an etalon.

An average 9 kilowatt-level direct-D2O-cooled side-pumped Nd:YAG multi-disk laser resonator at QCW mode with a pulse width of 250μs is presented, in which the straight-through geometry adopted oscillating propagates through 40 thin disks and multiple cooling D2O flow layers Brewster angle. Much attention has been paid on design gain module, including an analysis loss disk. Experimentally, output highest energy more than 20 J obtained repetition frequency 10 Hz. At high frequency, power 9.8...

A phase demodulation of dual-cavity fiber-optic Fabry-Perot interferometer based on open-cavity and silica-cavity was proposed experimentally demonstrated for pressure temperature sensing. In contrast to the commonly used wavelength demodulation, in this paper has advantages simplicity, rapidity high precision. By spatial frequency domain, sensitivity -2.07 rad/Mpa -5.48 x 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> rad/°C are...

We experimentally demonstrate, to the best of our knowledge, temperature and refractive index (RI) sensing with a novel L-like Michelson interferometer (MI). Two MIs are designed based on single-mode fiber (SMF) multimode (MMF), respectively, fabricated via an oxyhydrogen flame rotatable platform. By comparative experiments size bent degree sensor, corresponding parameters sensor excellent performance determined for measurement experiments. The RI sensitivity SMF MI reaches -131.0nm/RIU,...

By studying the theory of heat conduction, we established transient conduction equation for a pulsed laser diode (LD) end pumped thulium doped laser. Combined with actual working environment LD single-ended composite Tm:YAG rod, expressions temperature distribution and time-varying thermal focal length were obtained by integral transform method separation variables. Under 240 mJ pump energy repetition rates 80, 90, 100 Hz, effects in rod simulated, lens was measured experiments. The...

The wavefront of the output high power laser beam generated by a MOPA system with slab gain medium was measured and analyzed an H-S sensor, consisted static aberration whole optic chain dynamic component caused driver. Analyzing results showed that temporal frequency mostly less than 10Hz, but spatial distribution more challengeable to phase compensation. Due narrow rectangle shape none uniformity pumping cooling, it had some local big slope cross section, lot difficulties measuring...

A linearly polarized operation Ho:YAG laser at 2090.5nm with a corner cube cavity is demonstrated. polarizer high reflectivity for the s-polarized light wavelength employed to achieve laser. In same case of resonator length, can be used cut volume and enhance stability system. The maximum output power 5.8 W achieved absorbed pump 23.3 W, corresponding slope efficiency 29.7%, optical-optical conversion around 24.9%. M2 factors 2.09 μm are 2.4 1.2 along horizontal vertical directions, respectively.

We demonstrate a single-longitudinal-mode Ho3+:YVO4 unidirectional ring laser based on the acousto-optic effect, utilizing features of acousto-optical Q switch and half-wave plate to achieve operation. The maximum power achieved in at 2053.9 nm is 941 mW when absorbed set as 4.4 W, yielding nearly 50% slope efficiency. M2 factor 1.1. results show that such technique offers potentially promising new method for achieving high narrow linewidth 2 μm laser.

In this paper, we demonstrate a novel, to the best of our knowledge, transverse-load and high-temperature sensor based on cascaded Vernier effect. Two Fabry–Perot interferometers fabricated by piece hollow-core fiber (HCF) polarization-maintaining photonic crystal (PM-PCF) are connected long part single-mode with length 1 m, play roles sensor, respectively. The sensitivity not only transverse load but also that temperature can be enhanced is raised 7.7 times 5.84 nm/N, sensitivities...