The construction of an efficient and durable oxygen evolution reaction (OER) electrocatalyst through a simple synthesis strategy is crucial for the hydrogen produced from seawater splitting. However, achieving this goal remains great challenge. Herein, amorphous Fe-doped nickel phosphate (Fe-NixPO4) as high-performance OER electrocatalysts alkaline freshwater/seawater splitting presented using straightforward co-precipitation method at room-temperature. Experimental results reveal structural...

We developed an all-fiber-based optical demodulator for the signal interrogation of low-coherence fiber-optic Fabry-Perot interferometric sensors. The consists a Michelson interferometer implemented by using 3 × fiber coupler and two fiber-coupled Faraday reflectors with tunable delay lines. demodulator's output contains interference signals constant phase shift shows no sensitivity to polarization variation in light source or fibers. A digital recovery algorithm is used extract measurand...

It is known that photons produced by spontaneous parametric down-conversion can be coupled into optical fibers more efficiently focusing the pump field. We find in type-II causes of ordinary and extraordinary polarization to acquire very different angular spreads, which amounts spatial information distinguishes between states. Numerical studies predict collected a detector or quantum channel will predominantly one degree entanglement lessened some cases.

Thin carbon foils are used as strippers for charge exchange injection into high intensity proton rings. However, the stripping become radioactive and produce uncontrolled beam loss, which is one of main factors limiting power in Recently, we presented a scheme laser an ${\mathrm{H}}^{\ensuremath{-}}$ Spallation Neutron Source (SNS) ring. First, atoms converted to ${\mathrm{H}}^{0}$ by magnetic field, then excited from ground state upper levels laser, states protons field. In this paper...

We describe the measurement of fast dynamic strains in mercury target module spallation neutron source using customized high-radiation-tolerant fiber-optic strain sensors. The sensors are made from fluorine-doped single-mode optical fibers that demonstrated high radiation tolerance at 1300 nm. A digital phase demodulation scheme is employed signal interrogation system, which enables bandwidth and has an excellent adaptability to sensor output power fluctuations gap variations. Fast transient...

A high peak-power Q-switched laser has been used to monitor the ion beam profiles in superconducting linac at Spallation Neutron Source (SNS). The suffers from position drift due movement, vibration, or thermal effects on optical components 250-meter long transport line. We have designed, bench-tested, and implemented a stabilization system by using an Ethernet CMOS camera, computer image processing analysis, piezo-driven mirror platform. can respond frequencies up 30 Hz with detection...

We demonstrate a quadrature phase-shifted optical demodulation scheme for low-coherence fiber-optic Fabry-Perot interferometric sensors. The main part of the demodulator is Mach-Zehnder interferometer (MZI) constructed with 1 × 2 fiber coupler, 3 and delay lines. This configuration allows us to generate interference signals simultaneously, thus eliminating problem ambiguous phase discrimination. path length difference MZI adjustable adapt sensors arbitrary gaps. A great stability has been...

The effectiveness of small-bubble gas injection to mitigate cavitation-induced erosion damage and decrease strain in Spallation Neutron Source (SNS) target vessels was characterized using photography, laser-line scanning, in-situ vessel measurements. Observations from early targets showed that caused appreciable mass loss along the inner wall. Later designs incorporated a cavitation mitigation technique called injection, which small helium bubbles were introduced into flowing mercury during...

Pulsed lasers with pulse durations of nanosecond to millisecond are very important tools for free-space optical communication, LADAR, laser material processing, and sensing. Although Q-switched solid-state or gas currently the most popular light sources these purposes, pulsed semiconductor have potential above applications because their compactness, accessibility direct modulation, inherently large electrical conversion efficiency. The drawbacks high-power poor beam quality low coherence...

We describe an upgraded fiber-optic sensor system and its performance in measuring the dynamic strains a mercury target of Spallation Neutron Source (SNS). Strains result from pressure waves stainless-steel induced by short (~700 ns), intense (up to 23.3 kJ), high-energy (~1 GeV) proton pulses. In system, output each head is interrogated with compact, all-fiber based Faraday Michelson interferometer, which generates interference signals steady phase shift. Strain waveforms are recovered...

We report a doubly resonant enhancement cavity (DREC) that can realize simultaneous of two incoming laser beams at different wavelengths and temporal structures. The double-resonance condition is theoretically analyzed, DREC locking methods are experimentally investigated. Simultaneous Fabry-Perot to both an infrared (1064 nm) its frequency-tripled ultraviolet (355 pulses has been demonstrated by controlling the frequency difference between with fiber-optic shifter. technique enables novel...

Utilizing noninvasive 2D scans with laser wires, we tomographically reconstructed the 4D transverse phase space distribution of a 1-GeV hydrogen ion (i.e., ${\mathrm{H}}^{\ensuremath{-}}$) beam during operation. The tomography is based on two new advances. First, extended formulation maximum entropy to take projections as input and derived theoretical results relevant our application. Second, introduced method ``perpendicular scans'' obtain cross-plane information from wire emittance...

This paper presents a scheme for three-step laser-based stripping of an ${\mathrm{H}}^{\ensuremath{-}}$ beam charge exchange injection into high-intensity proton ring. First, atoms are converted to ${\mathrm{H}}^{0}$ by Lorentz in strong magnetic field, then neutral hydrogen excited from the ground state upper levels laser, and remaining electron, now more weakly bound, is stripped field. The energy spread particles gives rise Doppler broadened absorption linewidth, which makes inefficient...

We experimentally demonstrate the simultaneous injection locking of pairs high-power broad-area laser diodes in a 19-laser array driven by common current source. Each pair is locked use single-mode low-power semiconductor laser. The frequency and phase are verified optical spectrum interference pattern between injection-locked lasers. influence detuning on (simultaneous) behavior has been clarified. validate necessary condition for array.

A compact multifunctional optical correlator system for pulse width measurement of ultrashort ultraviolet (UV) pulses has been designed and experimentally demonstrated. Both autocorrelation cross-correlation functions are measured using a single nonlinear crystal, the switching between two measurements requires no adjustment phase matching detector. The can measure UV widths from sub-picoseconds to 100 ps, it involves auxiliary in measurement. results on burst-mode picosecond laser show...

Vibration analysis is generally used in the industries for condition monitoring of various electromechanical equipment. For predictive maintenance industry equipment, several techniques have been applied which are based on capacitive and piezoelectric accelerometers. However, they possess real time problems due to negative influence electromagnetic interference. The major problem lies detection transmission physical parameters noisy harsh environment. In order solve weak points commonly...

Optoelectronic hybrid bistability and multistability in an active interferometer using a laser diode are demonstrated experimentally. The laser-diode is composed of Twyman-Green with electronic feedback circuit. By feeding back the output together external light input through detector to control thelaser-diode injection current, optical bistable multistable states power from observed. Bistable operation does not require cutoff or saturation amplifier. theoretical background phenomena discussed.

A high power bottom-emitting InGaAs/GaAsP vertical-cavity surface-emitting laser with a large aperture (400 µm diameter) is described. The device has been fabricated by using oxidation confinement technology. threshold current 610 mA, and the maximum output up to watt regime (1.42 W) at room temperature (24 °C) pulse condition (pulse width of 50 µs, repetition rate 1 kHz). continuous wave optical as 1.09 W. lasing peak wavelength 987 nm, full half-maximum 0.9 far-field divergence angle below...

A new scheme with sequential resonant excitation for laser assisted charge exchange injection of ${\mathrm{H}}^{\ensuremath{-}}$ beams is proposed. In contrast the one step scheme, proposed requires significantly less power high efficiency stripping. It also provides greater flexibility in choice wavelength a given beam energy and extends range energies where stripping can be effectively applied. Calculations experimental plans 1.0 GeV 1.3 at Spallation Neutron Source are presented. Results...

A laser wire ion beam profile monitor system has been developed at the Spallation Neutron Source accelerator complex. The uses a single source to measure horizontal and vertical profiles of pulsed hydrogen (H(-)) along 230 m long superconducting linac, which accelerates H(-) from 200 MeV 1 GeV. In this paper, we describe optics requirement for system, performance measurement, effects parameters on measurement reliability. result provides practical guideline development large-scale,...

Charge exchange injection is the standard mechanism used to accumulate short, intense pulses of proton beams from an ${\mathrm{H}}^{\ensuremath{-}}$ injector into a synchrotron. Historically, this process has relied on foils remove two electrons ${\mathrm{H}}^{\ensuremath{-}}$, technique that been successfully employed for beam powers up 1.4 MW. However, such are known sublimate beyond threshold power density, requiring development another stripping technology does not have same limitation....

Single-photon light detection and ranging (LiDAR) provides high temporal resolution photon sensitivity, which are essential for long-range 3-D imaging. Despite important progress, LiDAR has yet to gain widespread adoption due the cost caused by poor yield complicated process of single-photon detectors. Here, we integrate a passive quenching resistor via wire bonding during packaging InGaAs/InP avalanche diodes (SPADs) propose corresponding readout circuit. The module can achieve 3.96%...