A central research area in nonlinear science is the study of instabilities that drive extreme events. Unfortunately, techniques for measuring such phenomena often provide only partial characterisation. For example, real-time studies optics frequently use spectral data, limiting knowledge associated temporal properties. Here, we show how machine learning can overcome this restriction to time-domain properties optical fibre modulation instability based on intensity measurements. Specifically,...

A quantitative and simultaneous measurement of K, KCl, KOH vapors from a burning fuel sample combusted in single particle reactor was performed using collinear photofragmentation atomic absorption spectroscopy (CPFAAS) with time resolution 0.2 s. The previously presented CPFAAS technique extended this work to cover two consecutive fragmentation pulses for the KCl KOH. spectral overlapping spectra is discussed, linear equation system correction interference introduced. detection limits KOH, K...

Metal nanoclusters consist of a few to hundred atoms and exhibit attractive molecular properties such as ultrasmall size, discrete energy levels, strong fluorescence. Although patterning these clusters down the micro- or nanoscale could lead applications high-density data storage, it has been reported only for inorganic matrices. Here we present submicron-scale mask-free fluorescent silver in an organic matrix. The were produced by direct laser writing poly(methacrylic acid) thin films...

We report the first photoacoustic detection scheme using an optical frequency comb - spectroscopy (OFC-PAS). OFC-PAS combines broad spectral coverage and high resolution of OFCs with small sample volume cantilever-enhanced PA detection. In OFC-PAS, a Fourier transform spectrometer (FTS) is used to modulate intensity exciting source at determined by its scanning speed. One FTS outputs directed cell other measured simultaneously photodiode normalize signal. The detector operates in...

We demonstrate cantilever-enhanced photoacoustic spectroscopy in the mid-infrared using a supercontinuum source. The approach is broadband and allows for higher signal intensity an enhanced signal-to-noise ratio as compared to systems employing conventional black body radiation sources. Using this technique, we perform spectroscopic measurements of full ro-vibrational band structure water vapor at 1900 nm methane 3300 with relative enhancement factors 70 19, respectively, when that use Our...

Soil carbon storage is a substantial factor in the global cycle. Carbon sequestration agricultural soils, and assessment validation of soil storage, are crucial for mitigation greenhouse gas emissions steering towards sustainable farming practices. Enforcement verification policies, methods, models require extensive monitoring capability. However, current conventional laboratory-based methods estimation laborious, expensive, time-consuming. In this work, we have developed compact, robust,...

Studying the elemental composition of aerosol particles on a single particle level is importance when determining internal and external mixing state population. We present field-deployable platform for analysis ambient using laser-induced breakdown spectroscopy (LIBS). The utilizes wideband spectrometer simultaneous multi-element detection size-amplification-aided charging (SAAC) efficient focusing via linear electrodynamic quadrupole (LEQ). Carefully designed emission collection system...

Positron annihilation spectroscopy was used to study GaAsN/GaAs epilayers. GaAsN layers were found contain Ga vacancies in defect complexes. The density of the vacancy complexes increases rapidly order 1018 cm−3 with increasing N composition and decreases after annealing at 700 °C. anticorrelation concentration integrated photoluminescence intensity suggests that act as nonradiative recombination centers.

Abstract Coherent broadband light generation has attracted massive attention due to its numerous applications ranging from metrology, sensing, and imaging communication. In general, spectral broadening is realized via third-order higher-order nonlinear optical processes (e.g., self-phase modulation, Raman transition, four-wave mixing, multiwave mixing), which are typically weak thus require a long interaction length the phase matching condition enhance efficient light-matter for...

An ultrasonic particle concentrator based on a standing-wave hemispherical resonator is combined with confocal laser-scanning fluorescence detection. The goal to perform ultrasensitive biomedical analysis by concentration of biologically active microspheres. consists 4 MHz focusing transducer the optically transparent plastic bottom disposable 96-well microplate platform. collects suspended microspheres into dense, single-layer aggregates at well-defined positions in sample vessel...

We demonstrate incoherent broadband cavity enhanced absorption spectroscopy in the mid-infrared wavelength range from 3000 to 3450 nm using an all-fiber based supercontinuum source. Multi-component gas detection is performed, and concentrations of acetylene methane are retrieved with sub-ppm accuracy. A linear response nominal observed, demonstrating feasibility method for sensing applications.

Alpha particles can be detected by measuring the radioluminescence light which they induce when absorbed in air. The is emitted near ultraviolet region nitrogen molecules excited secondary electrons. accurate knowledge of yield utmost importance for novel radiation detection applications utilizing this effect. Here, an alpha particle investigated as a function energy loss air first time. Also, total measured with carefully calibrated Pu emitter used experiments. obtained results consistently...

Self-mixing interferometry (SMI) represents a simple, robust, and self-aligned technique for metrology applications. Still, its applicability on diffuse targets is limited to distances up few meters. We present an enhanced approach based the detection of frequency-modulated (FM) self-mixing signal. The FM signal achieved using acetylene edge filter that maps laser frequency variations into intensity as wavelength tuned steep absorption profile. An experimental comparison between conventional...

High peak power, narrow linewidth sources continue to be in high demand. Fiber amplifiers are a compelling option scale power of long 100-ns-pulses because their compact size and robustness. Unfortunately, stimulated Brillouin scattering (SBS) limits fiber causing instability. We demonstrate SBS suppression for 130-ns pulses from 5 MHz seed laser amplifier by using tapered with large 50 µm diameter core the output. The longitudinal change induces frequency shift gain back-travelling Stokes...

Although luminescence of water during irradiations proton and carbon-ion lower energy than the Cerenkov-light threshold were found recently, sources not yet obvious. To estimate luminescence, we measured light spectrum estimated luminescence. Using an ultraviolet (UV) sensitive charge coupled device (CCD) camera, images beam by changing optical filters, derived spectra compared with calculated results. The intensity at Bragg peak region was decreased as wavelength proportional to ∼λ−2.0...

Remote detection of alpha emitters is achieved by measuring the secondary radioluminescence light (air fluorescence) that induced particles when absorbed in air. A telescope was used to collect photons a photomultiplier tube, which operated photon counting mode. Careful matching photocathode response and filter pass-band allows sensing faint emission brightly illuminated environment, essential for operative use. minimum detectable activity 4 kBq reached at 1 m distance 10 s time,...

Abstract Noble metal nanoclusters are ultrasmall nanomaterials with tunable properties and huge application potential; however, retaining their enhanced functionality is difficult as they readily lose without stabilization. Here, we demonstrate a facile synthesis of highly photostable silver in polymer thin film using visible light photoreduction. Furthermore, the different stages nanocluster formation investigated detail absorption fluorescence spectroscopy, microscopy, atomic force...

Online characterization of fungal and bacterial spores is important in various applications due to their health climatic relevance. The aim this study was demonstrate the capability combination electro-dynamic balance assisted laser-induced breakdown spectroscopy (LIBS) fluorescence (LIF) techniques for online detection single (Aspergillus versicolor Penicillium brevicompactum) bacteria (Bacillus aureus). method enabled sensitive repeatable LIBS analysis common elemental components (Ca, Na,...

A photoacoustic (PA) sensor has been developed for the detection of nitrogen dioxide (NO(2)). Ten amplitude-modulated high-power light emitting diodes (LEDs), a total optical power 9 W at 453 nm, are used to excite signal in NO(2). The LEDs attached circumference cylindrical PA cell. induced longitudinal acoustics waves detected using two electromechanical film stacks, located ends Background cancelation is achieved by phase-sensitive difference pressure transducers. approach allows improved...