Laser Research Papers - Academia.edu (original) (raw)

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- Physics, Laser, Spectroscopy, Photonics

The possibility of developing a photochemical setup on the basis of an optically pumped ammonia laser with an intracavity photoreactor is proved. The obtained values of the cavity 'implication' factor γ are comparable with those of intracavity systems based on a CO2 laser. The conditions for achieving the maximum energy in the focusing cavity are determined and the ways to control the shape of its caustic are indicated.

- by Paula Mendoza
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- Condensed Matter Physics, Laser, Atmospheric Aerosols, Quantum Electronics

Visible Laser Light Communication System (VLLC) is a wireless communication system, using laser as the medium. In the data transfer process, it is possible to have optical interference where 2 laser beams coincide with one point on the reflector. Research on the effect of laser source interference has been carried out by several researchers including mitigation actions to reduce its effects. This experiment uses 2 optical distance sensors that produce a laser with a wavelength of 650 nm with a power <=4.1 mW and with the direction of the laser beam both of them cross each other. To determine the effect of the interference of two laser beams when crossing the communication process in the visible light communication system, a reflector is used which can capture the two laser beams and the reflector can be shifted gradually so that a condition can be obtained where the two laser beams meet at one point. From the measurements made at the points after the laser beam crossing, the meas...

- by Pranoto Laksono
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- Materials Science, Optics, Laser, Optoelectronics

Laser-based direct metal addition (LBDMA) is a promising directed energy deposition technology that is well suited for the production of complex metal structures, low-volume manufacturing, and high-value component repair or modification. LBDMA is finding wide application in the automotive, biomedical, and aerospace industries. However, the process reliability and the repeatability of finished components are still problems. This work offers a solution by developing a sensing and control system for the robotically controlled 8-axis LBDMA system developed at the

- by Radovan Kovacevic
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- Materials Science, Laser, Additive Manufacturing

A general approach to generate dense nanostructure on various substrates has been investigated in this paper. During this process, so called pulsed laser induced confined vapor deposition (PLCVD), a pulsed laser irradiation with a transparent confinement was applied to various surfaces, such as gold thin film on silicon wafer, AA6061 alloy and silicon wafer. When a 20 nm thick Au film was irradiated by 3 kHz pulsed laser, a short-range ordered thin layer of nanoparticles with average diameter of 9.0 ± 3.5 nm and density of 43.8 × 10 10 cm −2 is observed. Highly dense alumina nanoparticles were deposited on surface of AA6061 alloy by PLCVD process. Several silicon nanostructures, such as nanoparticles and microrings, can be produced under different experimental conditions. The formation mechanisms of these nanostructures were also discussed.

- by Gary Cheng
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- Materials Science, Laser, Nanoparticle, Multidisciplinary

We have determined the nuclear charge radius of 11 Li by high-precision laser spectroscopy. The experiment was performed at the TRIUMF-ISAC facility where the 7 Li-11 Li isotope shift (IS) was measured in the 2s → 3s electronic transition using Doppler-free two-photon spectroscopy with a relative accuracy better than 10 −5 . The accuracy for the IS of the other lithium isotopes was also improved. The major portion of the IS's are caused by differences in nuclear mass, but changes in proton distribution also make small contributions. Comparing experimentally measured IS with sophisticated atomic calculation of purely mass-based shifts, including QED and relativistic effects, allows derivation of the nuclear charge radii. The radii are found to decrease monotonically from 6 Li to 9 Li, and then increase with 11 Li about 11 % larger than 9 Li. These results are a benchmark for the open question as to whether nuclear core excitation by halo neutrons is necessary to explain the large nuclear matter radius of 11 Li; thus, the results are compared with a number of nuclear structure models.

- by rodolfo sanchez
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- Laser Spectroscopy, Laser, Hyperfine Interactions, Nuclear Structure
- by Richard Vannoy
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- Laser, Autonomous Robotics, Robotics Navigation

We have developed a numerical code that, starting from far-field intensity measurements, is able to evaluate the excitation coefficients of the transverse modes in a laser system.Both the coherent and incoherent mode cases are addressed, and, while the incoherent case is shown to be equivalent to a linear problem, the coherent case is discussed through its equivalence to the phase-retrieval problem. Problems arising from both ill posedness and the nonlinearity are discussed in detail.The validity of our approach is confirmed by several numerical simulations and some experimental results on the characterization of a Q-switched Nd:YAG laser.

- by alessandra esposito
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- Mechanical Engineering, Materials Science, Optics, Laser

We report a single-wavelength 1060 nm distributed Bragg reflector laser with a record high single lateral mode optical power of 400 mW. These lasers are fabricated using a quantum well intermixing technique for the non-absorbing phase and... more

- by Kechang Song and +1
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- Materials Science, Laser, Optoelectronics, High Power

Purposeto introduce the Innovative Electronics Manufacturing Research Centre (IeMRC) Flagship Project: Integrated Optical and Electronic Interconnect PCB Manufacturing (OPCB), its objectives, its consortium of 3 Universities and 10 companies and to describe the university research being carried out. This paper briefly reviews the motivation for developing novel polymer formulations, fabrication techniques, layout design rules and characterisation techniques for hybrid electronic and optical printed circuit boards using multimode polymer optical waveguide interconnects.

- by Richard Pitwon
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- Nonlinear Fiber Optics, Laser, Computer Aided Design, Optical Waveguides

We have investigated the nonlinear optical interaction of uniform and kink states of a nematic and a ferrofluid-doped nematic (ferronematic) liquid crystal with an incident laser field. We find that the transition between the permitted uniform oreintational states of these systems is of first order in the case of nematics, and of second order in the case of ferronematics. In the latter case we also find the phenomenon of reentrance. We find new kink states in a magnetic field with topological winding different from π in the case of nematics, and 2π in the case of ferronematics. In ferronematics, due to grain segregation the phase diagrams for uniform and kink states are entirely different. In these systems we find a first or second order structural transformation from a single kink into a pair of kinks. Further, we obtain a rich variety of kink states as the intensity of the laser field is varied.

- by Srivatsa Krishnamurthy
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- Theoretical Physics, Laser, Nonlinear Optics, Solitons

Despite the advances in optical technologies for early detection of cancer, routine clinical applications are still not standardized. Among several optical methods, laser-induced fluorescence is a more matured and well understood technique. Still due care has to be taken about various factors to avoid erroneous results. The authors have carried out a systematic study on the effect of the various experimental parameters such as source stability, area of exposure, and angular/distance dependence of a fiber probe, which is ...

- by Sajan Daniel George
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- Materials Engineering, Materials Science, Laser, Manufacturing Engineering

To look forward to new trends in modern gas lasers and their applations, the results of current theoretical and experimental studies on search of new active media for high-power short-wavelength gasdynamic and chemical lasers are... more

- by Igor Izmailov and +1
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- Optics, Radiation, Laser Physics, Laser

Lab on Chip technologies have enabled the possibility of novel μTAS devices (micro Total Analysis System) that could drastically improve health care services for billions of people around the world. However, serious drawbacks that reside in fluid handling technology currently available for these systems often restrict the commercialization of such devices. This work demonstrates a novel fluid handling method as a possible alternative to current micropumping techniques for disposable microfluidic chips. This technology is based on a single use, low cost, thermal micropumping system in which expandable microsphere mixtures are activated by commercial grade laser diodes to achieve flow rates as high as 2.2 μl/s and total volumes over 160 μl. With the addition of a volume dependent shut off valve, nanoliter repeatability is realized. Pressure and heat transfer related data are presented. Finally, the possible prospects and limitations of this technology as a core element in unified optofluidic systems are discussed.

- by George Kanakaris
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- Microfluidics, Laser, Lab On A Chip, Optofluidics

Polytetrafluroethylene (PTFE) and other biocompatible polymers have been extensively used for sutures, vascular grafts and bone, and other hard tissue replacements. The use of surgical lasers for intervention on teflon-tissue interfaces has attracted a great deal of interest, as both the high intensity pulsed lasers and prosthetic biomaterials are in increasing use. The study of the ablational behaviour of PTFE films with three surgical lasers (CO2, Nd-YAG and XeCl) have been undertaken for assessing the optimal laser parameters for ablation (e.g. the absorption coefficient and the relevant threshold fluence) from ablation rate measurements.

- by Constantine Skordoulis and +1
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- Laser, Laser Ablation, Laser Ablation modeling

A regeneratively-cooled nozzle for liquid rocket engine applications is a significant cost of the overall engine due to the complexities of manufacturing a large thin-walled structure that must operate in extreme temperature and pressure environments. The National Aeronautics and Space Administration (NASA) has been investigating and advancing methods for fabrication of liquid rocket engine channel wall nozzles to realize further cost and schedule improvements over traditional techniques. The methods being evaluated are targeting increased scale required for current NASA and commercial space programs. Several advanced rapid fabrication methods are being investigated for forming of the inner liner, producing the coolant channels, closeout of the coolant channels, and fabrication of the manifolds. NASA's Marshall Space Flight Center (MSFC) has completed process development and subscale hot-fire testing of a series of these advanced fabrication channel wall nozzle technologies to gather performance data in a relevant environment. The primary fabrication technique being discussed in this paper is Laser Wire Direct Closeout (LWDC). This process has been developed to significantly reduce the time required for closeouts of regeneratively-cooled slotted liners. It allows for channel closeout to be formed in place in addition to the structural jacket without the need for channel fillers or complex tooling. Additional technologies were also tested as part of this program including water jet milling and arc-based additive manufacturing deposition. Each nozzle included different fabrication features, materials, and methods to demonstrate durability in a hot-fire environment. The results of design, fabrication, and hot-fire testing are discussed in this paper.

- by Paul Gradl
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- Materials Science, Manufacturing, Laser, Space Propulsion

The aim of this systematic review was to assess the efficacy of high intensity laser therapy (HILT) on wound surface area in patients with foot ulcers. [Methods] Four databases including PubMed, MED-LINE, the Cochrane library, and the Physiotherapy Evidence Database (PEDro) were searched up to the end of April 2018 to identify relevant studies. Studies were included if they met the following criteria: randomised controlled trial (RCT), assessed the efficacy of HILT in patients with foot ulcers, evaluated wound surface area, and written in English language with available full text. The PEDro scale was used to evaluate the quality of studies. [Results] A total of three RCTs met the inclusion criteria, with two studies of the efficacy of HILT in adult patients with diabetic foot ulcers and one in spina bifida children with neuropathic foot ulcers. According to the PEDro scale assessment, all three studies were rated as a fair quality. All studies found that HILT provided significantly better outcomes compared to sham laser or standard medical therapy. [Conclusion] This systematic review suggests that HILT is an effective modality for wound healing in patients with foot ulcers, but further large-scale studies are required to confirm its efficacy.

- by anwar ebid
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- Physiotherapy, Laser, Medicine, Low Level Laser Therapy

A recent development in the use of lidar remote sensing techniques is ground-based laser scanning. Laser scanning of rock faces yields the spatial relation between all scanned rock surface points, at a very high resolution, basically a dense "point cloud" in three-dimensional space. The subject of this research is to obtain discontinuity information from the point cloud data set, using an approach that can be automated. The first step in this methodology is to interpolate the point cloud data using 3D Delaunay triangulation in order to create a 3D surface. As a 3D triangulated surface, the scanned rock face is represented by a large number of triangles. The orientation of each triangle can subsequently be computed using basic geometrical rules. Analysis of the kernel density stereo plots of the orientation of all triangles, reveal that specific discontinuity sets can be recognised. Obviously, if this approach can be further developed and fully automated, this would give the site engineer or geologist, in realtime, evidence on the internal structure of any discontinuous rock mass. Particularly in areas where access to rock outcrops is poor, application of this technique will be very promising.

- by Robert H R G K Hack
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- Rock Mechanics, Geotechnical Engineering, Laser, LiDAR

Laser scanning confocal microscopy has become an invaluable tool for a wide range of investigations in the biological and medical sciences for imaging thin optical sections in living and fixed specimens ranging in thickness up to 100 micrometers. Modern instruments are equipped with 3-5 laser systems controlled by high-speed acousto-optic tunable filters (AOTFs), which allow very precise regulation of wavelength and excitation intensity. Coupled with photomultipliers that have high quantum efficiency in the near-ultraviolet, visible and near-infrared spectral regions, these microscopes are capable of examining fluorescence emission ranging from 400 to 750 nanometers. Instruments equipped with spectral imaging detection systems further refine the technique by enabling the examination and resolution of fluorophores with overlapping spectra as well as providing the ability to compensate for autofluorescence. Recent advances in fluorophore design have led to improved synthetic and naturally occurring molecular probes, including fluorescent proteins and quantum dots, which exhibit a high level of photostability and target specificity.

- by shivkanya phutke
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- Biophysics, Optics, Chemistry, Microscopy
- by Antoni Sanchez-Ferrer
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- Optics, Laser, Microsystems, Solid State NMR

Beam shaping and homogenization techniques are essential to optimize a large number of laser-material processing applications and laser-material interaction studies. In this paper, we present an innovative approach for modeling laser beam homogenization by means of the integration method. The numerical results are compared with experimental data, and the influence of the measurement technique is discussed. The enhancement of the homogenization capability using an asymmetric divider is also presented and discussed.

- by Paolo Di Lazzaro and +1
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- Optics, Laser, Optical Design, Laser beam shaping

Novel techniques for laser beam atmospheric extinction measurements, suitable for manned and unmanned
aerospace vehicle applications, are presented in this paper. Extinction measurements are essential to support the
engineering development and the operational employment of a variety of aerospace electro-optical sensor systems,
allowing calculation of the range performance attainable with such systems in current and likely future applications.
Such applications include ranging, weaponry, Earth remote sensing and possible planetary exploration missions
performed by satellites and unmanned flight vehicles. Unlike traditional LIDAR methods, the proposed techniques
are based on measurements of the laser energy (intensity and spatial distribution) incident on target surfaces of
known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for
radiance. Various laser sources can be employed with wavelengths from the visible to the far infrared portions of
the spectrum, allowing for data correlation and extended sensitivity. Errors affecting measurements performed
using the proposed methods are discussed in the paper and algorithms are proposed that allow a direct determination
of the atmospheric transmittance and spatial characteristics of the laser spot. These algorithms take into account a
variety of linear and non-linear propagation effects. Finally, results are presented relative to some experimental
activities performed to validate the proposed techniques. Particularly, data are presented relative to both ground and
flight trials performed with laser systems operating in the near infrared (NIR) at λ = 1064 nm and λ = 1550 nm.
This includes ground tests performed with 10 Hz and 20 KHz PRF NIR laser systems in a large variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft.

- by Roberto Sabatini
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- Aerospace Engineering, Laser, Atmospheric Aerosols, Aerospace
- by Santo I Situmorang
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- Physics, Music, Laser, Indonesia
- by Sean F Johnston
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- History of Science and Technology, Optics, Quantum Optics, History of Technology

techniques de laser de reglage pour carabine
http://www.puissantlaser.com/c-7/p-1308.html
Laser Classe II Puissance : 10mW
Longueur d'onde: 650 nm
Poids:50g
Longueur 155 mm. D
Diamètre de la têt: 16mm
Diamètre de la tige 4.3mm
Alliage d'aluminium supérieur T6061 finition noir mat.
Quatre adaptateurs de bouche réglables convenant aux calibres de 4.5/5.5/6.35/8.8mm

- by Mike vitiello
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- Laser

The article shows the possibilities of nondestructive testing of the subsurface structure of various objects by means of pulse thermography technique. A number of examples are presented and their structure is analyzed. The technique includes heating the surface of an object with laser radiation and pyrometric investigation of local changes in surface temperature. Information is extracted from thermography results obtained both during forced heating and during subsequent cooling of the sample. The main attention in the article is paid to parts made of plastics used as structural materials in a wide range of products.

- by Leonid Skvortsov
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- Remote Sensing, Laser, Non-destructive testing, Photothermal techniques

The analysis of the apparent source is used in laser safety to evaluate the retinal hazard. This study provides an analytic method to determine the location and size of the apparent source for laser beams. This method shows that the beam cross section at the center of curvature of the wave front at the eye lens can be considered the apparent source in terms of both the location and size. The approximation given by using the beam waist as the apparent source is examined and the error introduced by this approximation is evaluated. This analysis shows that the beam waist can be considered to be the apparent source only when the distance of the eye from the beam waist is much greater than the Rayleigh length of the beam. Examples showing the location and size of the apparent source are given for different beam characteristics and viewing distances. Measurement methods are also specified to provide an alternative to the analytic method.

- by Enrico Galbiati
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- Laser

Laser beam when expanded shows non-uniform illumination due to the presence of dust particles on mirrors and other optical elements. Due to coherence interference among the scattered beam is inevitable, leading to 'pits and valleys' some thing like moon's structure! So cleaning is needed as a prelude to the experiments to follow. This cleaning itself is an elaborate procedure which is discussed and shown. The shear interferometer patterns are shown with out any theory.

- by Sethuraman Jambunathan
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- Laser, Laser beam shaping, Spatial Filtering
- by Scott Sabreen
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- Materials Science, Plasma Physics, Polymer Chemistry, Polymer science

Planetary Defense is a complex problem, not well understood by policy makers and the general public. The recent Chelyabinsk incident in Russia created temporary international attention but has failed to effectively stimulate public action. The lack of long-term attention to cosmic hazards has resulted in limited funding to defend our planet. Hence, it is hard to realistically address this challenge and achieve the high test and operational readiness needed for an effective Planetary Defense strategy. To address this problem, we have created a set of recommendations for the development of a Planetary Defense Program, for the purpose of contributing to the protection of Earth from asteroids and comets. The SSP15 READI Project focused on threats for which there is only a short-term warning, specifically a warning of two years or less from detection of the object to impact. We have provided recommendations in five areas of Planetary Defense including detection and tracking, deflection techniques, global collaboration, outreach and education, and evacuation and recovery. We have applied this set of recommendations in a narrative scenario to make our report more impactful and engaging. We contrast optimistic and pessimistic outcomes for a comet threat, differing from each other in terms of the level of readiness achieved during the years leading up to the discovery of the threat. In our optimistic scenario, the deflection system has achieved high test and operational readiness. The world’s governments have realized the importance of being prepared against cosmic hazards and put in place all of the necessary measures for a successful defense, leading to a positive deflection of the comet. In contrast, in the pessimistic scenario no preparation is done before the detection, and the comet strikes a heavily populated area releasing energy equivalent to 80 times the most powerful nuclear bomb ever detonated. The recommendations that we have identified in this report constitute a roadmap to avoid this horrible outcome, and we believe they should be taken seriously and swiftly implemented.

- by Nikola Schmidt
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- Space Sciences, International Relations, Planetary Science, Laser

Abstract: CenterIMT Therapists have been using Laser Therapy for several years and are seeing significant improvements in ranges of motion, pain, inflammation, wound healing and other symptoms with the addition of this modality to the... more

- by Kimberly Burnham and +1
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- Laser, Posters, Integrative Manual Therapy

We present preliminary experimental results of making homogeneous the raw pulsed beam emitted by a large-aperture (10cm x 5cm) excimer laser. To this end, we use a novel optical system which is able to make homogeneous “bad beams” having strong local intensity spikes, and to modulate almost continuously the spot size of the homogenized beam along one or both axes in a fixed target plane. We have evaluated the results using the standard parameters described in the ISO 13694:2000. We found that the reliability of the results is dependent on a number of factors. In particular, we propose an amendment of the definitions of the edge steepness and plateau uniformity that could improve the reliability of these parameters.

- by Paolo Di Lazzaro and +2
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- Laser Physics, Laser, ISO standards, Laser beam shaping

The book includes the best-known techniques developed on the basis of the analysis of Russian and international clinical experience that were proven effective by international criteria and were approved by the Russian professional... more

- by Sergey Moskvin
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- Physiotherapy, Laser, Medicine, Lasers

Researchers have now shown that all these lasers can be replaced by a single device called a microcomb. [39] Femtosecond lasers are capable of processing any solid material with high quality and high precision using their ultrafast and ultra-intense characteristics. [38] To create the flying microlaser, the researchers launched laser light into a water-filled hollow core fiber to optically trap the microparticle. Like the materials used to make traditional lasers, the microparticle incorporates a gain medium. [37] Lasers that emit ultrashort pulses of light are critical components of technologies, including communications and industrial processing, and have been central to fundamental Nobel Prize-winning research in physics. [36] A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. [35] The unique platform, which is referred as a 4-D microscope, combines the sensitivity and high time-resolution of phase imaging with the specificity and high spatial resolution of fluorescence microscopy. [34] The experiment relied on a soliton frequency comb generated in a chip-based optical microresonator made from silicon nitride. [33] This scientific achievement toward more precise control and monitoring of light is highly interesting for miniaturizing optical devices for sensing and signal processing. [32] It may seem like such optical behavior would require bending the rules of physics, but in fact, scientists at MIT, Harvard University, and elsewhere have now demonstrated that photons can indeed be made to interact-an accomplishment that could open a path toward using photons in quantum computing, if not in light sabers. [31] Optical highways for light are at the heart of modern communications. But when it comes to guiding individual blips of light called photons, reliable transit is far less common. [30] Theoretical physicists propose to use negative interference to control heat flow in quantum devices. [29]

- by George Rajna
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- Laser
- by Wolfgang Tschacher
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- Self-Organization, Laser, Systems Theory, Synergetics

 Yarı-İletken LAZER'in keşfi.  Katı maddelerden yapılmış olmasına rağmen yarıiletken lazer hem enerji hem de pompalama mekanizmaları bakımından yalıtkan katkılı lazerleri oldukça farklıdır LAZERİN TARİHÇESİ  1964 J. E. GEUSIC, H. M. MARKOS, L G VAN UITEIT  Bell Laboratuarları  İlk çalışan Nd:YAG LAZER LAZERİN TARİHÇESİ 1969 G M DELCO Otomobil uygulamaları için üçlü lazerlerin ilk endüstriyel donanım 1970 NIKOLAI BASOV GRUBU Moskova Lebedev Laboratuarlarında Xenon (Xe) ile yapılan ilk Excimer LAZER 1974 J J EWING &C BRAU Avco Everet Laboratuarlı ilk nadir gaz halojenür excimer. 1977 JOHN M J MADEY GRUBU Stanford Üniversitesinde ilk serbest elektron lazeri.

- by Şerif Saygın
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- Laser, Solid state lasers, Lazer, Lasers

The ablation rates, as a function of the laser fluence, of the optically transparent polymers, Nylon-6,6 and PMMA, are reported using picosecond and subpicosecond laser pulses, obtained from a Regenerative Amplified Nd:YAG laser system. The laser pulses had a duration of 100 ps at 1064 and 532 nm wavelengths and 0.8 ps at 595 nm. The ablation rate results indicate a strong saturation behaviour for both polymers in the investigated irradiation conditions. The material removal is 2–3 times higher in the case of the visible (532 nm) picosecond laser ablation experiments. The surface topology of the polymers was also studied. The obtained Atomic Force Microscopy images reveal no mechanical damage in the inner ablation crater wall. The qualitative analysis of the ablation mechanism for ultrashort pulse laser irradiation reveals a combination of photochemically induced direct bond dissociation and a photothermal process due to the relaxation of the excited polymers within the vibrational levels of the ground state.

- by Constantine Skordoulis and +1
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- Laser, Femtosecond Laser, Laser Material Processing, Laser Ablation

3D Laser Marking Engraving System Software Operation Manual

- by Jian Liu
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- Laser

Lasers have been considered for space communications since their realization in 1960. Specific advancement were needed in component performance and system engineering particularly for space qualified hardware. Advances in system architecture, data formatting and component technology over the past 3 decades have made laser communications in space not only viable but also an attractive approach into inter-satellite link applications.
Laser communications offer a viable alternative to RF communications for inter-satellite links and other applications here high performance links are a necessity. High data rate, small antenna size, narrow beam designs and narrow field of view are characteristics of laser communications that offer a number of potential advantages for system design.
Most important in space laser communications has been the development of a reliable, high power, single mode laser diode as a directly modulable laser source. This technology advance offers the space laser communication system designer the flexibility to design very light weight , high bandwidth , low-cost communication payloads for satellites whose launch costs are a very strong function of launch weigh. This feature substantially reduces blockage of fields of view of most desirable areas on satellites.

- by Sruthi Narahari
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- Laser

Otomotiv teknolojisi günümüzde oldukça hızlı bir gelişim kaydederken; bu gelişimini bir çok sektörde olduğu gibi artan ihtiyaç ve yenilikçi tasarım taleplerine borçludur. Müşteri çeşitliliğine göre planlanması gereken tasarım çeşitliliği yanında, hızlı ve maliyeti düşük parçaların üretiminin sağlanması bu sektördeki oyuncuların temel problemlerindendir. Günümüzde gelişen lazer teknolojisi bu iki temel problemi çözmekte kullanılan en etkili yollardan birisi olup, kendi teknolojisini de otomotiv sanayisi ihtiyaçlarına göre her geçen gün geliştirmektedir. Öyle ki sokakta rastladığımız ya da kullandığımız modern araçlardan, üretim aşamasında lazer teknolojisi ile tanışmamış olanı yoktur. Lazer teknolojisi esnek bir teknoloji olup otomotiv sanayisinde bir çok noktada hızlı ve maliyet etkin bir çözüm olarak tercih edilmektedir. Otomotiv endüstrisinde üretim aşamalarında kullanılan tekniklerden; kesme, kaynak ve markalama işlemlerinde lazer teknolojisi geleneksel bir çok yöntemden daha etkin çözümler sunmaktadır.

- by Yigit Ozan Aydın
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- Laser, Lazer

The human hearing range is from 20 Hz to 20 kHz. However, many animals can hear much higher sound frequencies. Dolphins, especially, have a hearing range up to 300 kHz. To our knowledge, there is no data of a reported wide-band sound frequency earphone to satisfy both humans and animals. Here, we show that graphene earphones, packaged into commercial earphone casings can play sounds ranging from 100 Hz to 50 kHz. By using a one-step laser scribing technology, wafer-scale flexible graphene earphones can be obtained in 25 min. Compared with a normal commercial earphone, the graphene earphone has a wider frequency response (100 Hz to 50 kHz) and a three times lower fluctuation (±10 dB). A nonlinear effect exists in the graphene-generated sound frequency spectrum. This effect could be explained by the DC bias added to the input sine waves which may induce higher harmonics. Our numerical calculations show that the sound frequency emitted by graphene could reach up to 1 MHz. In addition, we have demonstrated that a dog wearing a graphene earphone could also be trained and controlled by 35 kHz sound waves. Our results show that graphene could be widely used to produce earphones for both humans and animals.

Non Traditional Machining notes

- by Shashidhar G S
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- Engineering, Mechanical Engineering, Laser, Non Traditional Machining