نتایج جستجو برای: laser beam effect
تعداد نتایج: 1894333 فیلتر نتایج به سال:
any change in the refractive index of a laser active medium can lead to serious degradation of beam quality, laser beam modes, laser performance and variation in the intensity distribution. alteration in the refractive index of laser active medium is especially notable in high power lasers. it is clear that in the laser beam production, the pumping agent induces a great amount of heat which...
In this article, M2 factor of a thin disk laser with unstable resonator in two regimes is calculated numerically. In the first case, thermal effects are ignored and the parameters of beam width, divergence angle, radius of wave front curvature and finally, M2 factor of laser beam are calculated by using generalized beam parameters. These calculations show that the beam quality of the laser is d...
laser is one of the sources that induce a biological effect in higher plants. the positive effect of laser on some crops has been proved. this research was carried out to study the effect of laser radiation on the accumulation of proline in spring wheat (triticum aestivum cv. kavir) under different nacl treatment levels. semi-coherent red beam, infrared beam and one-second harmonics of neodymiu...
Laser is one of the sources that induce a biological effect in higher plants. The positive effect of laser on some crops has been proved. This research was carried out to study the effect of laser radiation on the accumulation of proline in spring wheat (Triticum aestivum cv. Kavir) under different NaCl treatment levels. Semi-coherent red beam, infrared beam and one-second harmonics of Neodymiu...
This study aimed to evaluate Laser-cutting process of Mild Steel St37 sheets with two different thicknesses. In order to evaluate the quality of cutting edge and the depth of the area affected by the heat, several tests were conducted to determine the effect of parameters such as Laser power, Laser beam movement speed and pressure of axillary gas on the quality of cutting edge and the depth of ...
In this paper propagation of combined laser beam through atmosphere is investigated. Laser beam is combined via lens array arrangement. Turbulence is considered as an affecting factor of atmosphere and its effects on transverse coherence length (Fried parameter), peak intensity, propagation efficiency, and spot size of the laser beam is investigated. Coherent and incoherent combined beam are co...
Surface roughness in the welding processes is one of the important parameters in the laser welded metal connections which affects laser beam absorption directly. When the laser beam is irradiated to the surface of the base metal, the surface roughness plays an important role in the amount of beam absorption and the amount of melting achieved and directly affects the penetration depth. The main ...
the modulation response, relative intensity noise and frequency noise characteristics of qd lasers are investigated theoretically, in presence of an additional optical pumping. it is revealed that the modulation response of qd laser enhances under additional optical beam. by small signal analysis of the carriers' and photons' rates, it is proposed that by injecting excess carriers to ...
treatment with antimicrobial chemotherapeutic agents, alternative approaches such as lethal photosensitization are being used. the aim of this study was to evaluate the effect of visible light and laser beam radiation in conjugation with three different photosensitizers on the survival of two main periodontopathogenic bacteria including porphyromonas gingivalis and fusobacterium nucleatum in di...
Laser forming is a modern process which is mainly used for forming metals. Different Lasers are used in this regard that includes Nd: YAG and CO2. In this study, forming bi-layer sheets of Aluminum/Ceramic by Laser was investigated. Furthermore, effect of Uniform and Gaussian heat flux distribution in different power, velocity, and beam diameters on bending angle was studied. FEM simulation ind...
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