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- 摘要
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- 实验方案
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Peptide Conjugated CuS Nanocomposites for NIR Triggered Ablation of Pseudomonas aeruginosa Biofilm
摘要： The Gram-negative bacteria Pseudomonas aeruginosa is one famous bacterial strain owing to its ability to effectively form biofilms, which is a front-line mechanism of bacterial tolerance. Herein, the near-infrared-induced nanocomposites were one-step prepared by modifying copper sulfide nanoparticle with peptide to effectively eradicate Pseudomonas aeruginosa biofilm through electrostatic interaction, photodynamic effect and photothermal effect. These nanocomposites could rapidly adhere to the surface of bacteria, and irreversible damage the bacterial membrane under near-infrared laser irradiation. Furthermore, the nanocomposites could selectively eliminate bacteria over mammalian cell without distinct toxicity to NIH 3T3 cells. The nanocomposites will exert a far-reaching impact on the future design of biocompatible near-infrared-induced antibacterial agents, exhibiting its potential applications in Gram-negative bacteria and biofilm infections.
关键词： copper sulfide nanoparticles,near-infrared laser,Gram-negative bacterial biofilm,photothermal and photodynamic effect
更新于2025-11-14 17:03:37
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Laser damage characteristics of indium-tin-oxide film and polyimide film
摘要： This report focuses on the damage characteristics of the indium-tin-oxide (ITO) layer and the polyimide (PI) layer, which are two constituent components of a LCD. This investigation is different from the previous study, in which the alignment layer was deposited directly on a glass substrate. The PI alignment layer is pinned on the ITO film to imitate the structure of the LCD as much as possible in our current study. The damage process of the ITO/Glass sample involves melting, vaporization near the laser-induced damage threshold (LIDT), and removal at a higher fluence. However, the damage process of the PI/ITO/Glass sample involves thermally induced plastic deformation, followed by cooling when the irradiation fluence is near the LIDT, and rupture when the irradiation fluence is higher. The LIDTs of the PI/ITO/Glass samples, as determined by the on-line CCD detection technique, are higher than those of the ITO/Glass samples. The favorable mechanical properties of the PI are primarily responsible for this result.
关键词： PI film,ITO film,near-infrared laser damage
更新于2025-10-22 19:40:53
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Ultrafast energy absorption and photoexcitation of bulk plasmon in crystalline silicon subjected to intense near-infrared ultrashort laser pulses
摘要： We investigate the non-linear response and energy absorption in bulk silicon irradiated by intense 12-fs near-infrared laser pulses. Depending on the laser intensity, we distinguish two regimes of non-linear absorption of the laser energy: for low intensities, energy deposition and photoionization involve perturbative three-photon transition through the direct bandgap of silicon. For laser intensities near and above 1014 W/cm2, corresponding to photocarrier density of order 1022 cm?3, we find that absorption at near-infrared wavelengths is greatly enhanced due to excitation of bulk plasmon resonance. In this regime, the energy transfer to electrons exceeds a few times the thermal melting threshold of Si. The optical reflectivity of the photoexcited solid is found in good qualitative agreement with existing experimental data. In particular, the model predicts that the main features of the reflectivity curve of photoexcited Si as a function of the laser fluence are determined by the competition between state and band filling associated with Pauli exclusion principle and Drude free-carrier response. The non-linear response of the photoexcited solid is also investigated for irradiation of silicon with a sequence of two strong and temporary non-overlapping pulses. The cumulative effect of the two pulses is non-additive in terms of deposited energy. Photoionization and energy absorption on the leading edge of the second pulse is greatly enhanced due to free carrier absorption.
关键词： bulk silicon,optical reflectivity,photoexcited solid,near-infrared laser pulses,Drude free-carrier response,non-linear response,energy absorption,plasmon resonance
更新于2025-09-23 15:21:01
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Near-infrared laser driven white light continuum generation: materials, photophysical behaviours and applications
摘要： The pursuit of efficient light sources has stimulated continued effort in the search of materials and methods for generating white light emission. In addition to the white light produced by light-emitting diodes (LEDs) and fluorescent lamps that involves spectral conversion of high energy to low energy emission, recent studies showed that it was also possible to produce white visible light by irradiating different active materials with near-infrared (NIR) constant-wave (CW) lasers. In this review, we begin by introducing and categorizing different materials that exhibit NIR laser driven white light emission, including normal inorganic phosphors, organometallic compounds, graphene, etc. We then discuss the photophysical behavior of this process in terms of optical spectra, temperature evolution and photoelectric response. Different mechanisms of while light generation are analyzed afterwards, and the possibility of a more general physical picture of this process is discussed. This review is concluded with a summary of the current understanding and discussion on potential applications and future perspectives.
关键词： graphene,near-infrared laser,optical spectra,photoelectric response,organometallic compounds,temperature evolution,inorganic phosphors,photophysical behavior,white light emission
更新于2025-09-23 15:19:57
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Nonlinear Refraction of Dielectric Single Crystals under Excitation with Ultrashort Near-Infrared Laser Pulses
摘要： Nonlinear refraction in a number of crystals (KGW, KGW:Eu3+, Ba(NO3)2, BaWO4, PbMoO4, and CdWO4) that are promising for excitation of multifrequency stimulated Raman scattering is investigated by a single-beam Z-scan method. Picosecond laser pulses with a wavelength of 1064 nm generated by a YAG:Nd3+ laser were used for excitation of nonlinear optical processes. The values of n2 are compared depending on the type of the crystal, optical-axis orientation, and impurity concentration.
关键词： Z-scan method,Ultrashort near-infrared laser pulses,Dielectric single crystals,Nonlinear refraction,Stimulated Raman scattering
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Suppressing the Influence of CCD Vertical Blooming on M <sup>2</sup> Determination through Deep Learning
摘要： The vertical blooming of charge-coupled device (CCD) usually occurs in silicon-based cameras, which poses great challenge to determine the M2 of near-infrared (NIR) lasers. In this paper, a new method based on deep learning technique to suppress the influence of CCD vertical blooming on M2 determination is proposed for the first time, to the best of our knowledge. Taking a step-index few-mode fiber as an example, large amounts of samples including the blooming near-field beam patterns and their corresponding M2 values are used to train the convolutional neural network (CNN), aiming at learning a fast and accurate mapping from the beam pattern to the M2 parameter. The trained CNN can then be utilized to analyse the blooming pattern recorded by CCD to determine the M2. The simulated testing results have shown that the averaged prediction error of our scheme is about 0.5% for the investigated fiber beams. As for the time cost, our trained CNN only takes about 10 ms to determine the M2 value using a common laptop computer, indicating great real-time ability with high performance.
关键词： near-infrared laser,M2 parameter,deep learning,CCD vertical blooming
更新于2025-09-16 10:30:52
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AuNP and ssDNA capped mesoporous silica nanoparticles for laser controlled drug release
摘要： In order to improve drug e?cacy, and reduce drug toxicity and side e?ects, a novel drug controlled release system was developed based on mesoporous silica nanoparticles (MSNs) with gold nanoparticles (AuNPs) acting as pore caps and short single-stranded DNA (ssDNA) oligomers as the linker. The synthesised composites were characterized by Fourier transform infrared spectroscopy (FTIR), powder X-ray di?raction (XRD), thermogravimetric analysis (TGA), zeta potential measurement, transmission electron microscopy (TEM) and UV-vis spectroscopy. The anticancer drug doxorubicin (Dox) was applied as a model drug to investigate the 808 nm near infrared (NIR) laser-controlled drug release behavior at di?erent pH by ?uorescence measurements. The investigation results demonstrate that this nanocarrier could achieve drug controlled release by external near-infrared (NIR) laser stimulation, which is expected to be applied in cancer therapy.
关键词： doxorubicin,near-infrared laser,single-stranded DNA,mesoporous silica nanoparticles,drug controlled release,gold nanoparticles
更新于2025-09-16 10:30:52
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Development of a Near-infrared Laser-induced Surface Deformation Microscope and Its Application to the Dynamic Viscoelastic Measurements of Single Living Plant Cell Surfaces
摘要： A near-infrared laser-induced surface deformation (NIR-LISD) microscope is developed and is applied to the dynamic viscoelastic measurements of the surface of a living plant cell. In the microscope, the deformation of the surface is induced by an NIR laser beam, and then the change in intensity of the probe beam reflected from the surface reflects its viscoelasticity. The application of the NIR laser beam has a great advantage for the prevention of damage to the plant cell compared to the irradiation of a visible laser beam in LISD measurements. The NIR-LISD microscope allows for discriminating the differences in power spectra between the subapical and lateral regions of single rhizoids. It is a useful method for the dynamic viscoelastic measurements of cells, such as plant cells, that are damaged due to the strong absorption of ultraviolet or visible light.
关键词： plant cell,near-infrared laser,dynamic viscoelasticity,LISD microscope
更新于2025-09-11 14:15:04
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Parts-per-billion-level detection of hydrogen sulfide based on near-infrared all-optical photoacoustic spectroscopy
摘要： A highly sensitive trace hydrogen sulfide (H2S) gas sensing scheme based on all-optical photoacoustic spectroscopy is demonstrated. A high-power erbium-doped fiber amplified near-infrared laser is used as a light source for acoustic excitation. Meanwhile, the second-harmonic photoacoustic signal is measured by a fiber-optic cantilever microphone which is equipped with a white-light interferometric readout. For sensitivity improvement, the demodulated digital photoacoustic signal is processed by a virtual lock-in amplifier. The continuous H2S measurement experiment shows the ability of real-time response. A detection limit is achieved to be 33 ppb with a 10 s measurement time at the wavelength of 1576.29 nm. With both the excitation light and the probe light being transmitted by optical fibers, the designed sensing system has the advantages of remote detection and immunity to electromagnetic interference.
关键词： Trace gas detection,Photoacoustic spectroscopy,Fiber-optic sensing,Cantilever microphone,Near-infrared laser
更新于2025-09-10 09:29:36