Infrared Laser Research Articles

Single intraoperative infrared laser optimized bone repair in rat femoral osteotomies with experimentally induced osteoporosis.

This study aimed to evaluate the effect of infrared laser (IRL) on bone repair in ovariectomized rats subjected to femoral osteotomies. Of 32 rats, half underwent bilateral ovariectomy (OVX) and the other half underwent sham ovariectomy (SHAM). A period of 3months was defined to observe the presence of osteoporosis. The rats were subjected to osteotomies in the femurs and then fixed with a miniplate and 1.5-mm system screws. Thereafter, half of the rats from both SHAM and OVX groups were not irradiated, and the other half were irradiated by IRL using the following parameters: wavelength, 808nm; power, 100 mW; 60s for each point; 6J/point; and a total of 5 points of bone gap. All animals were euthanized 60days after surgery. The femur gap was scanned using micro-computed tomography (micro-CT). The samples were then examined under a confocal laser microscope to determine the amounts of calcein and alizarin red. The slides were stained with alizarin red and Stevenel's blue for histometric analysis. In the micro-CT analysis, the OVX groups had the lowest bone volume (P < 0.05). When the laser was applied to the OVX groups, bone turnover increased (P < 0.05). New bone formation (NBF) was comparable between SHAM and OVX/IR (P > 0.05) groups; however, it was less in the OVX groups (P < 0.05). In conclusion, the results encourage the use of IRL intraoperatively as it optimizes bone repair, mainly in animals with low bone mineral density.

The Use of Sacrificial Graphite-like Coating to Improve Fusion Efficiency of Copper in Selective Laser Melting

Thin and ultrathin carbon films reduce the laser energy required for copper powder fusion in selective laser melting (SLM). The low absorption of infrared (IR) radiation and its excellent thermal conductivity leads to an intricate combination of processing parameters to obtain high-quality printed parts in SLM. Two carbon-based sacrificial thin films were deposited onto copper to facilitate light absorption into the copper substrates. Graphite-like (3.5 µm) and ultra-thin (25 nm) amorphous carbon films were deposited by aerosol spraying and direct current magnetron sputtering, respectively. The melting was analyzed for several IR (1.06 µm) laser powers in order to observe the coating influence on the energy absorption. Scanning electron microscopy showed the topography and cross-section of the thermally affected area, electron backscatter diffraction provided the surface chemical composition of the films, and glow-discharge optical emission spectroscopy (GDOES) allowed the tracking of the in-deep chemical composition of the 3D printed parts using carbon film-covered copper. Ultra-thin films of a few tens of nanometers could reduce fusion energy by about 40%, enhanced by interferences phenomena. Despite the lower energy required, the melting maintained good quality and high wettability when using top carbon coatings. A copper part was SLM printed and associated with 25 nm of carbon deposition between two copper layers. The chemical composition analysis demonstrated that the carbon was intrinsically removed during the fusion process, preserving the high purity of the copper part.

Peroxidase-like MoS2/Ag nanosheets with synergistically enhanced NIR-responsive antibacterial activities.

Pathogenic microbial infections have been threatening public health all over the world, which makes it highly desirable to develop an antibiotics-free material for bacterial infection. In this paper, molybdenum disulfide (MoS2) nanosheets loaded with silver nanoparticles (Ag NPs) were constructed to inactive bacteria rapidly and efficiently in a short period under a near infrared (NIR) laser (660nm) in the presence of H2O2. The designed material presented favorable features of peroxidase-like ability and photodynamic property, which endowed it with fascinating antimicrobial capacity. Compared with free MoS2 nanosheets, the MoS2/Ag nanosheets (denoted as MoS2/Ag NSs) exhibited better antibacterial performance against Staphylococcus aureus by the generated reactive oxygen species (ROS) from both peroxidase-like catalysis and photodynamic, and the antibacterial efficiency of MoS2/Ag NSs could be further improved by increasing the amount of Ag. Results from cell culture tests proved that MoS2/Ag3 nanosheets had a negligible impact on cell growth. This work provided new insight into a promising method for eliminating bacteria without using antibiotics, and could serve as a candidate strategy for efficient disinfection to treat other bacterial infections.

FT-IR Analysis of P. aeruginosa Bacteria Inactivation by Femtosecond IR Laser Radiation.

We report the successful inactivation of P. aeruginosa strain by femtosecond infrared (IR) laser radiation at the resonant wavelengths of 3.15 μm and 6.04 μm, chosen due to the presence of characteristic molecular vibrations in the main structural elements of the bacterial cells in these spectral ranges: vibrations of amide groups in proteins (1500-1700 cm-1), and C-H vibrations in membrane proteins and lipids (2800-3000 cm-1). The underlying bactericidal structural molecular changes were revealed by the stationary Fourier-transform IR spectroscopy, with the spectral peaks parameters being obtained by Lorentzian fitting with the hidden peaks revealed by the second derivative calculations, while no visible damage to the cell membranes was identified by scanning and transmission electron microscopy.

Design and Construction of a Dust Detection System using Infrared Laser: The Case of Dust Storms in Baghdad in the Summer 2022

Iraq suffers from serious pollution with harmful particles that have important direct and indirect effects on human activities and human health. In this research, a system for detecting pollutants in the air was designed and manufactured using infrared laser technology. This system was used to detect the presence of pollutants in the dust storms that swept the city of Baghdad which could have a negative impact on human health and living organisms. The designed detection system based on the use of infrared laser (IR) with a wavelength of 1064 nm was used for the purposes of detecting pollutants based on the scattering of the laser beam from these pollutants. The system was aligned to obtain the best signal for the scattered rays, which were detected using a digital storage oscilloscope. These studies were conducted during the dust storms that occurred intensely in Baghdad in the months (April, May, June and July) of the year 2022. Where multiple samples were taken at different periods in these storms, measurements were also done during the storm. The types of polluting elements found in the dust of the storms are: carbon, bromine, chlorine, hydrocarbons alcohol, ether, hydroxyl group, carbon, C=C (aromatic ring), nitrogen dioxide (aromatic nitro), and carbon monoxide. The value ​​of dust pollutant concentrations is (125.67 mg. m-3).

Infrared-to-visible conversion in strontium sulphate through a defect-based infrared stimulated visible emission phenomenon.

Strontium sulphate (SrSO4 ) is a defect-based photoluminescence material, generally used in thermoluminescence applications, and has been studied for infrared (IR) stimulated visible emission. The SrSO4 particles were synthesized using a precipitation method. The orthorhombic phase of SrSO4 was confirmed from the X-ray diffraction pattern and the formation of micron-sized particles was authenticated from field emission scanning electron micrographs. The elemental composition of oxygen and strontium was determined using energy-dispersive X-ray analysis measurement that confirmed the presence of and intrinsic defects in the material. Photoluminescence investigations showed the presence of various defect bands in the band gap giving rise to intrinsic luminescence in SrSO4 . The emission in the visible region was attributed to the defect band arising due to . Photoluminescence lifetime measurement confirmed the presence of stable defect states with a lifetime in microseconds. The SrSO4 sample was tested using IR lasers and a red-orange emission spot was observed from the powder sample when excited with IR lasers. The underlying principle for IR-to-visible conversion in the material is a defect-mediated phenomenon that has been described through the energy level diagram of the material.

Dual pulsed laser deposition system for the growth of complex materials and heterostructures.

Here, we present an integrated ultra-high-vacuum (UHV) apparatus for the growth of complex materials and heterostructures. The specific growth technique is the Pulsed Laser Deposition (PLD) by means of a dual-laser source based on an excimer KrF ultraviolet and solid-state Nd:YAG infra-red lasers. By taking advantage of the two laser sources-both lasers can be independently used within the deposition chambers-a large number of different materials-ranging from oxides to metals, to selenides, and others-can be successfully grown in the form of thin films and heterostructures. All of the samples can be in situ transferred between the deposition chambers and the analysis chambers by using vessels and holders' manipulators. The apparatus also offers the possibility to transfer samples to remote instrumentation under UHV conditions by means of commercially available UHV-suitcases. The dual-PLD operates for in-house research as well as user facility in combination with the Advanced Photo-electric Effect beamline at the Elettra synchrotron radiation facility in Trieste and allows synchrotron-based photo-emission as well as x-ray absorption experiments on pristine films and heterostructures.

Assessment of the Use of Infrared Laser for Dynamic Laser Speckle (DLS) Technique

Dynamic laser speckle (DLS) analysis is a very sensitive technique to measure biological activity within samples. In agriculture, the technique is applied to monitor seed germination, but external light, water content, and pigments affect the measurements. DLS systems use visible light sources, typically red lasers, which may exacerbate their influences. The main objective of this work is to assess whether infrared (IR) lasers improve the robustness of DLS measurements in seed germination applications. We develop a system where DLS analysis can be performed simultaneously on visible and IR light. Using the system, we quantify how the DLS signal is affected by pigments and scattering. The results show that the use of IR light reduces the variability of the measurements acquired. DLS systems based on IR light appear to be less sensitive to pigments, and the greater penetration of IR light into samples, which is due to reduced scattering, may contribute to the signal collected being correlated to relevant biological processes within the inner tissue. Additionally, water activity provides less influence on the DLS signal when an IR laser is used. These findings support the wider use of IR lasers in DLS-based instruments for applications in biological samples.

Femtosecond infra-red laser carbonization and ablation of polyimide for fabrication of Kirigami inspired strain sensor

Microfabrication of polyimide (PI) with femtosecond laser of wavelength 1030 nm is studied in two process conditions. Firstly, the low power-low scan speed regime is investigated for laser carbonization producing piezoresistive laser induced graphene (LIG). The heat accumulation model is modelled to find the temporal evolution of temperature at the laser focus for a single laser scan. Secondly, the high power-high scan speed regime is studied for laser ablation where clean ablation was observed due to multiphoton absorption. To demonstrate the application of this process, a two-dimensional (2D) LIG based strain sensor is drawn on a Kapton PI sheet using laser carbonization and transformed into a three-dimensional (3D) conformal sensor by cutting into a Kirigami design using laser ablation. The strain in the sensor is calculated from finite element analysis and the gauge factor is 88.58 ± 0.16. This laser process enables the transformation of any 2D PI sheet into a 3D conformal sensor using femtosecond laser, which is useful for wearable sensors and health-monitoring applications. The fabricated sensor is demonstrated used on a knee-joint to monitor real-time tracking of bending and twisting knee movements.

RGB color camera for dynamical measurements of high temperature distribution on a surface of the heated solid

In this report we describe a fast 3-color method of the measurement of temperature distributions on a surface of a heated solid using a RGB color camera with a high frame rate (100 images per second). Statistical error the RGB method is not high, and do not exceed around 5.5% which is surprising taking in to account the number of the measurements at each pixel. Comparison of the results of the temperature measurements on a tungsten plate heated by infra-red laser radiation and conducted with this technique and those obtained with the acousto-optical tunable filter technique demonstrate that error of the temperature measured by 3-color method is only two times as high as that of the tandem acousto-optic filter technique method.

Tool-Wear-Estimation System in Milling Using Multi-View CNN Based on Reflected Infrared Images.

A novel method for tool wear estimation in milling using infrared (IR) laser vision and a deep-learning algorithm is proposed and demonstrated. The measurement device employs an IR line laser to irradiate the tool focal point at angles of -7.5°, 0.0°, and +7.5° to the vertical plane, and three cameras are placed at 45° intervals around the tool to collect the reflected IR light at different locations. For the processing materials and methods, a dry processing method was applied to a 100 mm × 100 mm × 40 mm SDK-11 workpiece through end milling and downward cutting using a TH308 insert. This device uses the diffused light reflected off the surface of a rotating tool roughened by flank wear, and a polarization filter is considered. As the measured tool wear images exhibit a low dynamic range of exposure, high dynamic range (HDR) images are obtained using an exposure fusion method. Finally, tool wear is estimated from the images using a multi-view convolutional neural network. As shown in the results of the estimated tool wear, a mean absolute error (MAE) of prediction error calculated was to be 9.5~35.21 μm. The proposed method can improve machining efficiency by reducing the downtime for tool wear measurement and by increasing tool life utilization.

Laser debinding of parts produced through material extrusion additive manufacturing

A novel cost effective material extrusion additive manufacturing method for metals and ceramics employs filaments embedded with powdered granules which are shaped, debinded, and sintered sequentially until completion of the part. One well known drawback of the technology lies in the time-consuming debinding process, which often requires handling toxic agents (e.g. acetone, cyclohexane, nitric or oxalic acids), as well as complex heating profiles. Debinding is traditionally done after shaping the part, and little investigation has been made to develop the technology to debind locally, in situ, without the use of toxic consumables. Here, we show that full debinding can be achieved efficiently on the bulk of the printed part through an application of local energy by applying it selectively on the top surface, layer by layer, along the 3D volume of as built green parts. A low intensity infra-red laser is integrated in a custom-built machine to create a hybrid device that combines traditional filament extrusion additive manufacturing with in-situ debinding. The results show that the main binder matrix of a Highly Filled (HF) commercially available stainless steel 316L filament can be removed efficiently along the full volume of the part via laser ablation of the organic mass. Defects, surface roughness and topography deviations can be minimized compared to other traditional thermal debinding methods, further showcasing the capability of building consecutive layers on top of a previously debinded layer. We report improvements in debinding time by a magnitude of 248 % compared to traditional thermal debinding, of 595 % compared to solvent debinding at 45 °C, and 943 % compared to solvent debinding at room temperature. The effect of debinding with the use of lasers in-situ, layer by layer, and the effect in the layer adhesion of fully debinded parts, is investigated through optical and electron microscopy, as well as quantifying the binder mass loss. Debinding in-situ offers new routes to reduce processing times of parts produced through FFF.

Expression and degranulation of mast cells in laser photobiomodulated mucositis chemo-induced: pilot study in hamsters

This study aimed to evaluate the influence of laser photobiomodulation on the expression and degranulation of mast cells in chemo-induced oral mucositis (OM) lesions in hamsters. Twelve adult male Syrian hamsters (Mesocricetus auratus), golden lineage, were submitted to OM induction. They were divided into three groups: control-OM without treatment (C), OM treated with red laser (RL), OM treated with infrared laser (IL) and analyzed in the experimental time of 7 days. Three and 4 days after the intraperitoneal injection of the chemotherapy drug fluorouracil, the OM lesions were induced by making grooves in the right cheek pouch. Immediately after chemoinduction, the hamsters were submitted to photobiomodulation every 48 h for 7 days. The specimens were processed and stained using the hematoxylin-eosin and toluidine blue techniques. There was a predominance of mild chronic inflammation in the experimental groups and a greater persistence of neutrophils in the control group (C), although not statistically significant. The group irradiated with red laser (RL) had the highest mean mast cell expression (38.28 ± 19.05) (p < 0.001). As for the degranulation activity in mast cells, the control group (C) showed a greater number of fields with more than 50% of degranulated cells, presenting statistical significance when comparing it with the RL (p < 0.009) and IL (p = 0.036) group. It can be concluded that photobiomodulation, at both wavelengths, decreased mast cell degranulation, accelerating the inflammatory process. The use of infrared laser provided, in addition to less degranulation, the quantitative reduction of mast cells.

Simulation and Analysis of Temperature Field During Oxidation Layer Preparation on Titanium Alloy Using Infrared Laser

Simulation and Analysis of Temperature Field During Oxidation Layer Preparation on Titanium Alloy Using Infrared Laser

Dielectric Laser Accelerators Driven by Ultrashort, Ultraintense Long-Wave Infrared Lasers

Particle acceleration driven by intense lasers has long been a frontier of research in the field of laser engineering physics due to its extremely high acceleration gradient. Recently, dielectric laser accelerators (DLAs) have become a new research hotspot due to their ability to achieve gigavolt-per-meter acceleration gradients on compact chip-level all-optical structures. In comparison to the currently widely used solid-state laser with a 1-μm wavelength, long-wave infrared (LWIR) lasers with a length of about 10 μm offer several unique advantages, including the ability to obtain a large electric charge of particle beams and lower energy divergence. These advantages have been validated in plasma-based laser accelerators as well as DLAs. Although the system is still in its early stages of development, the use of LWIR lasers for driving DLAs has special significance, including but not limited to easier processing of optical chips and larger acceleration channels. This review will provide a detailed introduction to this field from 2 aspects: DLAs and ultrashort and ultraintense LWIR lasers based on CO 2 laser amplifiers.

Cisplatin-loaded gold nanoshells mediate chemo-photothermal therapy against primary and distal lung cancers growth

Lung cancer is the most common cause of cancer mortality worldwide. The advances in surgery, radiotherapy, chemotherapeutic and immunotherapeutic drugs have progressed in the past decades, but the prognosis of lung cancer is still poor. In this study, we developed cisplatin (CDDP)-loaded human serum albumin (HSA)-based gold nanoshells (HCP@GNSs) for synergistic chemo-photothermal therapy (chemo-PTT). The HCP@GNSs not only acted as drug nanocarriers for chemotherapy but also serve as a superior mediator for PTT, which could exhibit a temperature increase upon a near infrared (NIR) laser exposure that was sufficient for photothermal ablation. HCP@GNSs were highly biocompatible and hemocompatible nanocarriers, while the synergistic chemo-PTT resulting from HCP@GNSs plus NIR exposure displayed stronger cytotoxicity effect than HCP@GNSs or PTT alone, especially at a low CDDP concentration. In vivo analysis demonstrated that HCP@GNSs-mediated chemo-PTT increased necrosis in tumors to achieve a high tumor clearance rate with no adverse side effects. Moreover, HCP@GNSs-medicated chemo-PTT induced the recruitment of dendritic cells, B-cells, and natural killer T-cells in distal tumors to inhibit the growth of the tumors. Therefore, the CDDP-loaded HCP@GNSs may be a potential nanomedicine candidate for curative lung cancer treatment in the future.

Design and characterisation of the JadePix-3 CMOS pixel sensor

The JadePix-3 CMOS pixel sensors have been developed and studied with a design optimised for a high position resolution of 3μm, which is one of the key requirements for the physics programmes at the Circular Electron-Positron Collider (CEPC) experiments. The sensors are orientated to the vertex detector for the experiments at the proposed future CEPC. The sensors with high-resistance substrates were produced using Tower Semiconductor’s 180 nm CMOS Imaging Sensor (CIS) process, which feature small sensing diodes, low power analogue front-ends with an in-pixel discriminator, and a rolling shutter readout scheme to minimise the pixel pitch. In the sensors, the pixel matrix of 512 rows × 192 columns is divided into four sectors with varied pixel size (16μm×26μm and 16μm×23.11μm) and circuit design. Electrical pulse tests reveal that for various sectors, the minimum thresholds range from 90 to 140 e, with a noise hit rate below an upper limit of 1 × 10−10/frame/pixel. An infra-red laser beam and a radioactive source of 90Sr have been used to characterise the sensors. The tests show that with the equivalent threshold charge fixed to 220 e−, a position resolution between pitch/212 and pitch/12 can be achieved by tuning the laser power for a signal charge between 440 e− and 880 e−. The measured power consumption is 127 mW for the JadePix-3 sensor and 87 mW/cm 2 when extrapolated to a large sensor of 1 cm × 2.5 cm.

Fenton-driven photothermal enhanced degradation of methylene blue by using Cu2O@SnO2@PDA cubic heterostructured catalyst

In order to enhance the photostability of Cuprous oxide and improve the photocatalytic activity, this study was the first to prepare polydopamine (PDA) coated Cu2O@SnO2 Fenton heterostructured catalyst (HCs) for photothermal synergistic enhanced pollutant dye degradation. HCs reduced the Cu2O electron-hole pair filling group rate by Cu/Sn heterostructures, and the PDA shell layer protection greatly improved the stability of Cu2O. The developed Cu2O@SnO2@PDA-HCs could generate heat rapidly under near infrared (NIR) laser irradiation, which greatly improved the catalytic efficiency of the catalyst by a typical photothermal enhanced Fenton-driven degradation process. All the results indicate that Cu2O@SnO2@PDA-HCs have great potential applications in dye wastewater treatment.

Ultrafast Dissociation Dynamics Induced in [Fe(CO)5] n Xe m Mixed Clusters by Resonant Femtosecond Infrared Laser Radiation.

Real-time dissociation dynamics induced in [Fe(CO)5] n Xe m mixed molecular clusters by femtosecond IR radiation in the 5 μm region was studied for the first time by means of time-resolved methods based on resonant excitation of C≡O vibrations in the molecular core of the cluster and photoionization probing (λ = 400 nm) of its decay products. It was found that IR-excited clusters in the initially cold particle beam are heated and dissociated as a result of relaxation processes, giving rise to free neutral Xe aggregates and Fe(CO)5 molecules. Thus, the formed particles are the origin of signal variations from Xe+ and Fe(CO)5 + ions, which grow on a picosecond time scale. It is concluded that the initial laser excitation of C≡O vibrations in clusterized molecules is followed by the process of cluster dissociation accompanied with the formation of free neutral particles according to the hierarchy of binding energies: weakly bound shells of Xe atoms are evaporated first and much faster than the Fe(CO)5 molecules from the cluster core. The characteristic times of relaxation processes as well as the cluster temperature were estimated.

Picosecond Infrared Laser Mass Spectrometry Identifies a Metabolite Array for 10 s Diagnosis of Select Skin Cancer Types: A Proof-of-Concept Feasibility Study.

Currently, a large number of skin biopsies are taken for each true skin cancer case detected, creating a need for a rapid, high sensitivity, and specificity skin cancer detection tool to reduce the number of unnecessary biopsies taken from benign tissue. Picosecond infrared laser mass spectrometry (PIRL-MS) using a hand-held sampling probe is reported to detect and classify melanoma, squamous cell carcinoma, and normal skin with average sensitivity and specificity values of 86-95% and 91-98%, respectively (at a 95% confidence level) solely requiring 10 s or less of total data collection and analysis time. Classifications are not adversely affected by specimen's quantity of melanin pigments and are mediated by a number of metabolic lipids, further identified herein as potential biomarkers for skin cancer-type differentiation, 19 of which were sufficient here (as a fully characterized metabolite array) to provide high specificity and sensitivity classification of skin cancer types. In situ detection was demonstrated in an intradermal melanoma mouse model wherein in vivo sampling did not cause significant discomfort. PIRL-MS sampling is further shown to be compatible with downstream gross histopathologic evaluations despite loss of tissue from the immediate laser sampling site(s) and can be configured using selective laser pulses to avoid thermal damage to normal skin. Therefore, PIRL-MS may be employed as a decision-support tool to reduce both the subjectivity of clinical diagnosis and the number of unnecessary biopsies currently required for skin cancer screening.