Liquid Laser Research Articles

Laser transfer for circulating tumor cell isolation in liquid biopsy.

75Cancer research has found in the recent years a formidable ally in liquid biopsy, a noninvasive technique that allows the study of circulating tumor cells (CTCs) and biomolecules involved in the dynamics of cancer spread like cell-free nucleid acids or tumor-derived extracellular vesicles. However, single-cell isolation of CTCs with high viability for further genetic, phenotypic, and morphological characterization remains a challenge. We present a new approach for single CTC isolation in enriched blood samples using a liquid laser transfer (LLT) process, adapted from standard laser direct write techniques. In order to completely preserve the cells from direct laser irradiation, we used an ultraviolet laser to produce a blister-actuated laser-induced forward transfer process (BA-LIFT). Using a plasma-treated polyimide layer for blister generation, we completely shield the sample from the incident laser beam. The optical transparency of the polyimide allows direct cell targeting using a simplified optical setup, in which the laser irradiation module, standard imaging, and fluorescence imaging share a common optical path. Peripheral blood mononuclear cells (PBMCs) were identified by fluorescent markers, while target cancer cells remained unstained. As a proof of concept, we were able to isolate single MDA-MB-231 cancer cells using this negative selection process. Unstained target cells were isolated and culture while their DNA was sent for single-cell sequencing (SCS). Our approach appears to be an effective approach to isolate single CTCs, preserving cell characteristics in terms of cell viability and potential for further SCS.

Photomechanical Laser Fragmentation of IrO2 Microparticles for the Synthesis of Active and Redox‐Sensitive Colloidal Nanoclusters (Small 10/2023)

Active and Redox-Sensitive Colloidal Nanoclusters In article number 2206485, Stephan Barcikowski, Heinz Paul Huber, and co-workers track microparticle laser fragmentation processes all along the timescale from picoseconds to milliseconds. They discover the unprecedented efficiency to yield ultrasmall particles, exceeding current laser synthesis’ productivities by one order of magnitude. (Cover art shows AI-painted “Advanced Nanoparticle Generation and Excitation by Lasers in Liquids”, created by J. Barcikowski, F. Barcikowski, and S. Barcikowski using DiscoArt-DiscoDiffusion.)

The Influence of Ablation Speed on the Synthesis of Carbon Nanostructures Via Pulsed Laser Ablation of Asphalt in Ethanol

Pulsed liquid laser ablation is considered a green method for the synthesis of nanostructures because there are no byproducts formed after the ablation. In this paper, a fiber laser of wavelength 1.064 µm, peak power of 1 mJ, pulse duration of 120 ns, and repetition rate of 20 kHz, was used to produce carbon nanostructures including carbon nanospheres and carbon nanorods from the ablation of asphalt in ethanol at ablation speeds of (100, 75, 50, 10 mm/s). The morphology, composition and optical properties of the synthesized samples were studied experimentally using FESEM, HRTEM, EDS, and UV-vis spectrophotometer. Results showed that the band gap energy decreased with decreasing the ablation speed (increasing the ablation time), the minimum mean particle size of the synthesized samples was 76 nm at an ablation speed of 100mm/s, while the maximum mean particle size was 98 nm at ablation speed of 50 mm/s, the nanospheres were agglomerated to form larger spherical nanoshapes. All the synthesized carbon nano colloids exhibited a blue-green PL emission. It was concluded that the presence of carbon nanorods has an effect on the optical properties of the synthesized nanospheres.

Methylene blue degradation using ZnO:CuO:Al2O3 nanocomposite synthesized by liquid laser ablation

Methylene blue degradation using ZnO:CuO:Al2O3 nanocomposite synthesized by liquid laser ablation

A New Generation of Liquid Lasers from Engineered Semiconductor Nanocrystals with Giant Optical Gain

AbstractWith the development of optofluidic technology, liquid lasers have attracted intense interest but still face a formidable challenge due to the lack of qualified gain media and creative device design. Compared to the organic fluorescent dyes and traditional CdSe‐based nanocrystals (NCs), the lead‐halide perovskite (LHP) NCs feature larger gain coefficient and higher robustness, which renders LHP NCs a promising unexploited liquid gain medium. Herein, for the first time, the hidden principle governing the solution‐based light amplification in LHP semiconductor NCs is demystified and it is demonstrated that the LHP NCs are superior solution‐phase gain media showing a giant (≈2600 cm−1) optical gain. On this basis, a novel microfluidic laser device is designed and realized that exhibits a record‐low pump threshold (≈22.7 µJ cm−2), high Q‐factor (≈7480), large output polarization (≈0.91), and long‐time robustness over high‐intensity operation, which is readily applicable to practical applications. The findings represent a significant step toward the technologically important liquid lasers of the new generation and can advance optofluidic applications.

Спектральные и люминесцентные свойства Yb-=SUP=-3+-=/SUP=- в растворах CCl_4-GaCl_3-Yb-=SUP=-3+-=/SUP=-

The absorption and luminescence spectra and the luminescence lifetime of the excited state 2F5/2 of Yb3+ ions in CCl4 – GaCl3 – Yb3+ solutions have been measured. Information was obtained on the Stark splitting of levels, on the absorption and stimulated emission cross sections, and on the quantum yield of Yb3+ luminescence. The spectral dependences of the gain cross section are calculated for different relative inverse populations of the 2F5/2 excited state. Based on an analysis of the spectral and laser properties of Yb3+, it was concluded that the use of CCl4 – GaCl3 – Yb3+ solutions as the active medium of a liquid ytterbium laser is promising. Keywords: carbon tetrachloride, ytterbium, absorption, luminescence, lifetimes, Stark splitting, gain cross section

Highly efficient hexagonal-phase Nd3+ doped KLaF4 nanoparticles colloidal suspension for liquid lasers

Innovative approach in the exploration of high-power liquid laser media, utilizing hexagonal KLaF4: x% Nd3+ (x = 1–30 mol%) nanoparticle colloidal solutions synthesized from one-step chemical route is hereby presented. The phase purity and nano size distributions of the nanoparticles are confirmed from X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM). The concentration dependent absorption and steady-state and dynamic infrared emission (at 1058 nm, 4F3/2 → 4I11/2) features of Nd3+ ion of KLaF4: x% Nd3+ liquid media are closely examined. The estimated stimulated emission cross-sections, branching ratios and quantum efficiencies establishes the potentiality of these hexagonal nanoparticle colloidal solutions for high power liquid laser applications. Inokuti-Hirayama (I–H) and diffusion dominated Yokota-Tanimoto (Y-T) models are employed to examine the dynamic emission evolution of KLaF4: x% Nd3+ (x ≥ 5–30 mol%). The proposed study substantiate that the colloidal solution can serve as a new laser media for low-cost and high-energy liquid lasers and amplifiers.

The Efficacy of New Liquid Laser Dye Material – Chalcone: 1-(4-methylsulfonyl phenyl)-3-(4-N,N-dimethyl (amino phenyl)-2-propen-1-one (MSPPP)

This paper includes the efficacy of synthesis and characterization of a new liquid laser dye material – chalcone of 1-(4-methylsulfonyl phenyl)-3-(4-N,N-dimethyl (amino phenyl)-2-propen-1-one (MSPPP) and its application as a new laser medium. The absorption and fluorescence spectra of MSPPP were investigated under different solvents and concentrations. The study investigated the pump pulse energies of Nd: YAG laser (355 nm) and the amplified spontaneous emission (ASE) performance of MSPPP under various concentrations, and organic solvents. At identical conditions, the amplified spontaneous emission spectra of MSPPP in solution were compared with a conventional laser dye of coumarin 503. The fluorescence quantum yield and the gain of MSPPP were determined. The features are: (I) MSPPP has stellar photochemical stabilization., (II) ASE from the MSPPP was setting in the wavelength range between 515 and 548 nm. The molecular geometry was optimized and their HOMO– LUMO energy values were determined by SCM Software for Chemistry & Materials using DFTB (GGA BLYP) [Density-Functional based Tight-Binding] method.

Improvement of superhydrophobicity and durability of EP+PDMS/SiO2 composite coatings by adjusting laser curing powers

The lack of durability in superhydrophobic coatings has restricted the practical applications of coatings in the fields of marine and construction. In this paper, the composite coatings of epoxy resin (EP), polydimethylsiloxane (PDMS) and SiO2 nanoparticles were prepared by using the room-temperature liquid spraying and laser curing methods. The effects of the laser curing powers on the microstructure, hydrophobicity, durability in terms of corrosion and friction of the coatings were researched. The results demonstrate that there were micropores and aggregated SiO2 nanoparticles on the surface of coatings. The coatings had the growth structure with SiO2 nanoparticles partially embedded into the PDMS and EP bottom layer, and PDMS in the bottom layer migrating upward. With the increase of laser curing powers, the nanoparticles gathered significantly and the micropores was decreased. Under different laser curing powers, the coatings had the Si-(CH3)2 hydrophobic group and exhibited superhydrophobicity. All the coatings showed excellent self-cleaning performance in muddy water and ink. As the laser curing power increased, the superhydrophobicity of the coating was increased (the maximum contact angle of the coating was up to 161.90 ± 1.85°). Moreover, the coatings had strong corrosion resistance after being immersed in artificial seawater for 72 h. The coatings still had the superhydrophobicity after 100 cycles of load friction. With the increase of laser curing power, the friction resistance of the coating was improved, and the corrosion resistance was first improved and then reduced. This study provides a new idea for obtaining superhydrophobic and strong durable coatings.

Laser ablation of a solid target in liquid medium for beryllium nanoparticles synthesis

In this paper, we describe a method to synthesize beryllium (Be) nanoparticles (NPs) by laser ablation of a solid target immersed in a liquid medium. Beryllium dust was successfully synthesized following the irradiation of a Be bulk target, which was immersed in water, acetone or heavy water, respectively, using the first and second harmonic (1064 and 532 nm) of a Nd: YAG laser source providing ns pulses, with a repetition rate of 10 Hz. The laser fluences used for Be target ablation were 8 and 15 J/cm2. In order to argue the successful obtaining of Be dust, scanning electron microscopy (SEM) was used for surface analysis. Colloidal solutions analysis by dynamic light scattering (DLS) supports the SEM analysis in terms of NPs size, whereas chemical analysis by X-ray photoelectron spectroscopy (XPS) was used in order to investigate the chemical composition. Moreover, thermal desorption spectroscopy (TDS) was performed on Be dust synthesized in heavy water to study the retention of deuterium (D). The key parameters for obtaining much sharper and regular size distribution were identified as being the liquid medium, laser fluence, and wavelength.

Thermal analysis of side-pumped direct-liquid-cooled Nd: YAG thin-disk lasers

Thermal effects are the main obstacle for side-pumped direct-liquid-cooled Nd: YAG thin-disk lasers (SDNTDLs) to achieve high-power near-diffraction-limited laser output. A multiphysics model is established and several basic understandings are obtained. The temperature distribution of the disk under lateral non-uniform pumping shows that the total reflection transmission of the pump lights in the disk does not result in severe temperature fluctuations. The thickness of the thermal boundary layer is much less than half the thickness of the fluid, indicating that there is no thermal interaction between two adjacent disks. The component analysis of the thermally-induced wavefront aberration (TIWA) reveals that the influence of the fluid’s thermo-optic effect (TOE) which is awful in liquid lasers is not necessarily dominant in SDNTDLS due to the thin thermal boundary layer. When cooled by D2O, the wavefront aberration induced by the disk is much larger than that induced by the fluid. As a result, the TIWA exhibits a distribution of high at both sides and low at the center along the transverse direction of the disk, which is consistent with the experimental results. The wavefront aberration induced by the fluid’s TOE and that induced by the disk’s both TOE and deformation compensate for each other, indicating that the beam quality can be significantly improved by means of design optimization.

A coherence random lasing for gain media based on lnP/ZnS quantum dots

We report here a random lasing from the dye-doped media with the lnP/ZnS quantum dots. The lnP/ZnS quantum dots assistant optical feedback for random lasing emission through multiple scattering centers. Changing the energies of pump, the tunable lasing operation ranging from single photoluminescence mode to many lasing modes. The tunability of the central wavelength is realized by altering the constraint structure of the devices, and the wavelength ranges are changed from 600 nm to 635 nm. Besides, it is the first time, our quantum dots liquid crystal random lasers design holds great potential for the liquid crystal display of lasers, as well as for the promising material of liquid crystal lasers.

Linear Optical Properties of Organic Laser Dye Doped with PMMA Polymer

In this work, linear optical characteristics of Azure B organic laser dye doped with PMMA polymer dissolved in DMF solvent at concentration (1×10-3 M) were studied. This research includes presenting the results and discussing the absorption spectra and linear optical properties (transmission, linear absorption and refraction coefficient), by studying the effect of adding polymer (PMMA) with different ratios on this pure dye. The result showed that possibility of using this dye in liquid state laser.

Highly photo-stable, kHz-repetition-rate, diode pumped circulation-free liquid dye laser with thermal lens management

Liquid dye lasers have long been considered as ideal tunable laser sources in the visible range but are bulky, expensive, and require a complex system for dye circulation. Here, we present a system that relies on a low-cost blue laser diode as the pump source and a sealed dye cell with no flowing circuitry, resulting in a device that combines the convenience and size of a solid-state device with the stability of a liquid organic laser. A very high photo-stability is obtained (up to 1.2 × 109 pulses or 12 days at 1 kHz), which is five orders of magnitude higher than a solid-state dye laser operated in similar conditions. The number of pulses obtainable at low repetition rates is found to be limited by molecular self-diffusion and, hence, related to the total cuvette volume. In contrast, the repetition rate is limited to a few kHz, which suggests that thermal effects play a bigger role than triplet population effects. Thermal effects participate in the suppression of lasing through the buildup of a strong negative thermal lens; correcting the non-aberrant part of this thermal lens by resonator design enables the repetition rate to be pushed up to 14 kHz with possible further optimization. This work shows a route for building off-the-shelf, compact, low-cost, and convenient tunable pulsed lasers in the visible range that have superior stability over organic solid-state lasers.

Ultrahigh-Throughput Sample Analysis Using Liquid Atmospheric Pressure Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry.

Mass spectrometry (MS) allows for automated analysis of complex samples at high resolution without the need for labeling/derivatization. Liquid atmospheric pressure matrix-assisted laser desorption/ionization (LAP-MALDI) enables rapid sample preparation and MS analysis using microtiter-plate formats and high-performing mass spectrometers. We present a step change in high-speed, large-scale MS sample analysis of peptides at 20 samples/s and an enzymatic assay at 40 samples/s, i.e., an order of magnitude faster than current MS platforms. LAP-MALDI requires only low amounts of sample volume (<2 μL), of which only a fraction (<1%) is typically consumed, and allows for multiplexing and high-speed MS/MS analysis, demonstrated at ∼10 samples/s. Its high ion signal stability and similarity to electrospray ionization enables CVs below 10% and the analysis of multiply charged peptide ions at these extreme speeds. LAP-MALDI MS fulfills the speed requirements for large-scale population diagnostics and compound screening with the potential of analyzing >1 million samples per day.

Stable and Efficient Coupling of High-Power Continuous-Wave Laser With Uncooled Anti-Resonant Hollow-Core Fibers With End Caps

Hollow-core fibers provide an ideal environment for the interaction of a laser and gases; however, achieving stable and efficient coupling of a high-power laser is one of the key problems to be solved. Here, we study stable and efficient coupling of a high-power continuous-wave fiber laser with anti-resonant hollow-core fibers spliced with end caps. By optimizing the splicing process, a maximum laser power of 460 W was injected and 356.5 W was outputted under uncooled conditions, realizing a total transmission efficiency of approximately 77.5%. A test of more than 1 h showed the stability of this a coupling method. A few other important characteristics, such as the Fresnel reflection of the end caps and the influence of the end caps on the transmission beam quality, were measured and examined. This study opens new opportunities for stable and highly efficient coupling of high-power lasers with hollow-core fibers, which is significant for their applications in many other fields besides high-power fiber gas lasers, such as high-power laser delivery and liquid lasers in hollow-core fibers.

Features of photoconductivity and luminescence of CdS thin films and Cd-=SUB=-1-x-=/SUB=-Zn-=SUB=-x-=/SUB=-S solid solutions under laser excitation

The features of photoconductivity and luminescence of CdS thin films and Cd1-xZnxS solid solutions obtained by chemical pulverization with subsequent pyrolysis under laser excitation have been studied experimentally. Pulsed liquid (473-547 nm) and nitrogen (337 nm) lasers were used as a radiation source. An experimental study was made of the photoconductivity and photoluminescence spectra of Cd1-xZnxS thin films depending on the composition x at different excitation intensities and the relaxation curves of nonequilibrium photoconductivity. It is shown that the observed features in the photoconductivity and photoluminescence spectra of Cd1-xZnxS thin films are due to direct band-to-band transitions. Amplification of light is observed at high intensities of optical excitation in thin CdS films. Keywords: Thin films CdS, Cd1-xZnxS, laser, photoconductivity spectra, photoluminescence

Effect of liquid medium and laser processing parameters on the fabrication of carbon nanoparticles via pulsed laser ablation in liquid towards paper electronics

Paper-based electronics with carbon nanomaterials incorporated have several advantages including recyclability, biodegradability, non-toxicity, low cost and ease of fabrication and disposal. Herein, carbon nanoparticles (CNPs) were fabricated by Pulsed Laser Ablation in Liquid (PLAL) using three different liquid mediums, i.e. deionised (DI) water, ethanol and a magnesium-based solution. The as-fabricated nanocolloids were used as conductive inks and deposited on paper substrates. The resulting nanoparticle (NP) coatings were subjected to electrical resistivity tests via 4-point probe. Ultraviolet–Visible spectroscopy (UV–Vis) studies were conducted to determine the presence of nanomaterials. All nanocolloids produced within DI water had three distinct UV–Vis absorbance peaks at 200, 216 and 225 nm while nanocolloids produced in ethanol exhibited more peaks and significantly higher absorbance values in the range from 210 nm to 300 nm. Dynamic Light Scattering and field emission scanning electron microscopy (FESEM) were used to analyse samples for particle size and morphology respectively. The liquid medium in which PLAL was conducted was found to significantly affect the NP mean size, conductivity and surface chemistry of the resulting NPs. DI water produced smaller nanoparticles (NPs) (10–82 nm) than ethanol (60–143 nm) and magnesium-based solution (263–1389 nm) within the process parameters studied herein. The laser scan speed and fluence have a combined effect on the NP mean diameter. The surface chemistry of the NPs produced in the magnesium-based solution was analysed via X-ray photoelectron spectroscopy and it was found that the Mg, Li and Si atoms are adsorbed by the carbon NPs leading to higher conductivity of the coated paper substrates.

Numerical and experimental investigation of laser shock microhydroforming technology for microforming thin-walled LA103Z alloy foil with complex microfeatures

In this work, laser shock microhydroforming technology was further investigated. This technology employs liquid as the laser-induced shock wave transmission medium to microform a thin-walled LA103Z magnesium–lithium (Mg-Li) alloy foil with six bump features. A finite element model established by Hypermesh/LS-DYNA was used to illustrate the dynamic transmission of the liquid shock wave and the dynamic plastic deformation of the workpiece. The mechanism by which the liquid shock wave interacted with the closed liquid chamber to generate a homogenised shock wavefront was revealed. The dynamic loading form of the liquid shock wave and the characteristics of the microfeatures of the workpiece resulting from this dynamic loading form were also analysed mechanically. A comparison of the effects of liquid type and laser energy in this process showed that using castor oil as the liquid medium at threshold laser energy achieved the best plastic forming effect of the workpiece. Analysis of the thickness distribution of the workpiece revealed that the rupture was concentrated in the shear thinning region at the edge of the bump features caused by the transient large stress when the laser energy exceeded the threshold value.

Photophysical properties of highly green luminescent Tb(III) complexes

This article reports four Tb(III) green luminescent complexes based on the ligand 4-oxochromene-3-carbaldehyde and other synergistic ligands. Sharp peaks in the X-ray diffractogram confirms the crystalline property of the complexes. Four characteristic emission peaks of Tb(III) ion at ~499 nm, 545 nm, 586 nm, and 621 nm, assignable to 5D4→7F6,5,4,3 transitions, respectively, were obtained in photoluminescence spectra when irradiated at 345 nm. Bright green emission by the complexes was due to the dominant 5D4→7F5 peak at 545 nm. Ternary complexes exhibited improved thermal stability, emission intensities, quantum yield, and lifetime compared to the binary complex. Our investigations demonstrated that the prepared complexes might be practically useful in display devices, lighting systems, OLEDs, and liquid lasers due to their fascinating photometric properties.