scholarly journals Increasing of Pulsed Laser Source Peak Power by Use of Ring Fiber-Optic Delay Line

2019 ◽  
Vol 10 (2) ◽  
pp. 151-159
Author(s):  
V. A. Alekseev ◽  
M. R. Zaripov ◽  
A. S. Perminov ◽  
E. A. Sitnikova ◽  
V. P. Usol’tsev ◽  
...  

At the present time, developing of autonomous laser systems requires increasing of the output power of the laser sources used in composition of those systems and at the same time reducing of the energy usage in the system. The possibility of increasing output peak power of pulsed laser sources by using the method of synchronous non-coherent beam combining in ring fiber-optic delay line is considered by authors. Objective of this work was estimating energy effectiveness of laser systems, which based on this method.General constructing method of the laser pulsed laser source with ring fiber delay line is considered, its block diagram and the general operating principle of similar systems are presented. Two versions of laser systems based on the described method of beam combining are presented: using an optical combiner and an optical switch; using fiber welding instead of a combiner and an optical switch. The graphical dependence of the energy effectiveness on the number of circulations in ring fiber-optic delay line is obtained for both versions of laser systems.As a result of the analysis of the considered devices operation, it was shown that considered systems allow to obtain increasing the peak power of a laser pulse without increasing the power supply, also the system, that use welded fi instead of the optical combiner, has greater effi than system with optical combiner.

2021 ◽  
Author(s):  
huseyin ozgur kazanci ◽  
Kiichi Niitsu

Abstract The variation of photon fluence distributions [photon/cm2.s] for different input angle laser sources was shown by researchers experimentally [1]. According to this philosophy, different input angle source and detector photon entrance from tissue surface into imaging media have different photon fluence distributions for a specific tissue type. In this study, different input angle simulations were used for pulsed laser photons which uses time resolved (TR) Monte Carlo (MC) photon-tissue interaction simulation program to prove the philosophy in TR run mode. TR run mode MC simulation program trmc.c [2] was modified and used to generate TR photon counts inside the homogenous simulation environment. It has homogeneous tissue optical properties, absorption μa = 0.1 cm-1, scattering μs = 100 cm-1, and anisotropy g = 0.90 coefficients. Multi-input angle philosophy was first demonstrated by the researchers [1]. It was defined and experimentally proven. Photon fluencies which are forward model weight matrix coefficients differences were successfully shown for TR laser as a general procedure. In this study, differences were drawn for seven different input angle sources with pulsed laser photons. The proof-of-concept philosophy was shown successfully. The purpose of the use of pulsed laser is to show the righteousness of the philosophy in TR run mode, since the TR diffuse optical tomography (TRDOT) device would be made as a biomedical optic imaging (BOI) device. Cylindrical radial coordinate system which was defined in trmc.c [2] in earlier was used, the code was modified, and photon fluencies were generated based on the different input angle laser photons. Cylindrical coordinate system has 1 cm and 36-element radial r, and depth z grids. 100.000 photons were sent from pencil beam tissue surface point. Photons would be thought as group of ultra-narrow band pulsed laser photons. The main purpose of showing photon fluencies for different laser source input angles were succeeded and image reconstruction procedure was also applied. Ten time series were used which are [4, 8, 12, 16, 22, 26, 30, 38, 46, 52] picoseconds (ps). Different input angle photon fluence distribution figures were drawn. These are 0º, 15º, 30º, 45º, 60º, 75º, 90º. Photon fluence differences were also drawn and observed for different input angle laser sources. Forward model problem different input angle laser source and detector transfer functions were also drawn. Finally inlusion was embedded inside the homogenous simulation environment and images were reconstructed for both scenarios and localization error (LE), and concentration error (CE) was calculated for both scenarions and compared with each other.


2018 ◽  
Vol 85 (12) ◽  
pp. 746 ◽  
Author(s):  
V. A. Alekseev ◽  
A. S. Perminov ◽  
S. I. Yuran

Author(s):  
Florian Kuisat ◽  
Fernando Lasagni ◽  
Andrés Fabián Lasagni

AbstractIt is well known that the surface topography of a part can affect its mechanical performance, which is typical in additive manufacturing. In this context, we report about the surface modification of additive manufactured components made of Titanium 64 (Ti64) and Scalmalloy®, using a pulsed laser, with the aim of reducing their surface roughness. In our experiments, a nanosecond-pulsed infrared laser source with variable pulse durations between 8 and 200 ns was applied. The impact of varying a large number of parameters on the surface quality of the smoothed areas was investigated. The results demonstrated a reduction of surface roughness Sa by more than 80% for Titanium 64 and by 65% for Scalmalloy® samples. This allows to extend the applicability of additive manufactured components beyond the current state of the art and break new ground for the application in various industrial applications such as in aerospace.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hazem M. El-Hageen ◽  
P.G. Kuppusamy ◽  
Aadel M. Alatwi ◽  
M. Sivaram ◽  
Z. Ahamed Yasar ◽  
...  

AbstractDifferent types of laser source modulation techniques have been used in various applications depending on the objective. As optical systems extract the laws and the best solutions from experiments and simulations, the present study uses simulation software with different modulation types so the output signals can be compared. The modulators used are Mach-Zehnder, which is an external modulator, and electro-absorption modulator and laser rate equation modulator, which are direct modulators. All these types have an optical link multimode (MM) fiber with a photodiode in the receiver end that can be modeled. The input and output signals are analyzed using different types of modulations.


1979 ◽  
Vol 18 (15) ◽  
pp. 2555 ◽  
Author(s):  
D. A. Woodbury ◽  
T. A. Rabson ◽  
F. K. Tittel
Keyword(s):  

1994 ◽  
Vol 6 (6) ◽  
pp. 741-743 ◽  
Author(s):  
G.A. Ball ◽  
W.H. Glenn ◽  
W.W. Morey
Keyword(s):  

2006 ◽  
Vol 49 ◽  
pp. 56-61 ◽  
Author(s):  
Joseph J. Beltrano ◽  
Lorenzo Torrisi ◽  
Anna Maria Visco ◽  
Nino Campo ◽  
E. Rapisarda

A Nd:YAG laser is employed to ablate different materials useful in the bio-medical field. The laser source operates in the IR (1064 nm), VIS (532 nm) and UV (355 nm) regions with a pulse duration of 3-9 ns, a pulse energy of 3-300 mJ, a spot size of 1 mm2 and a repetition rate of 1- 30 Hz. Target material of interest are Titanium, Carbon, Hydroxyapatite (HA) and Polyethylene (PE). Laser irradiation occurs in vacuum, where hot plasma is generated, and thin films are deposited on near substrates. Generally, substrates of silicon, titanium, titanium-alloys and polymers were employed. Biocompatible thin films are investigated with different surface techniques, such as IR spectroscopy, Raman spectroscopy, XRD analysis and SEM investigations. Depending of the kind of possible application, films require special properties concerning the grain size, porosity, uniformity, wetting, hardness, adhesion, crystallinity and composition. The obtained results will be presented and discussed with particular regard to HA..


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