نتایج جستجو برای: laser beam

تعداد نتایج: 283190  

Saeed Olyaee, Shahram Mohammad Nejad,

In this paper, we present a high accuracy laser range finder and velocimeter using ultra-fast time-to-digital converter (TDC). The system operation is based on the measuring the round-trip time of a narrow laser pulse. A low-dark current high-speed PIN photodiode is used to detect the triggered laser beam and to produce start signal. The pulsed laser diode generates 45W optical power at 30ns du...

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 ...

H. R. M Khalesifard, J. Mostafavi-Amjad,

Micro-channels are made over the Ag+/Na+ ion-exchanged soda-lime glass surface by interaction of an intense Ar+ laser beam and the silver ions inside the glass matrix. The Ar+ laser beam reduces the Ag+ ions inside the matrix. The Ag+ atoms aggregate into silver nano-clusters around the interaction area, inside the glass matrix. Aggregation of the silver atoms and the thermal effects of the int...

Laser diode beam divergence is the main parameter for beam shaping and fiber optic coupling. Increasing the waveguide layer thickness is the conventional method to decrease the beam divergence. In this paper, the broadened asymmetric waveguide is introduced to decrease the divergence without increasing the optical power. The asymmetric waveguide was used to shift the vertical optical field to n...

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 ...

Journal: :cell journal 0

introduction: laser pointers are devices that produce a weak laser beam of 630-680 nmwavelength and 1-5 mw power (classii or iii a laser). these devices generally emit a redbeam that is used by lecturers and teachers for presentations. some children use pointers astoys and sometimes direct the beam to their own or others' eyes. material and methods: following irradiation by a laser pointer beam...

Aryabod Elham

Introduction: In laser surgery, the laser beam can evaporate and cut the tissue like a small surgical knife when the tissue temperature is heated to 100 degrees Celsius. a complete understanding of the distribution of damage in both pathologic tissue and surrounding tissue is necessary. Although the test is the most realistic solution for treating medical problems, for this rea...

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 ...

M. H. Haji Mirsaeidi, Sh. Mohammad Nejad,

In this paper altitude measurement from water surface using laser beam is presented. Research data indicate that the reflection of infrared waves from water surface is about zero and it is less than 2% for visible radiations. Phase-shift and heterodyne technique was used for the measurement, and the laser beam ( mW p nm 10 , 700 = = l ) was modulated by a sine wave having a fixed frequency....

شعبان, مجتبی , مجلس آرا, محمدحسین ,

In this research we measure some of the optical parameters of Barium Titanate crystal (BaTiO3), such as signal beam gain, coupling constant (exponential gain coefficient), change in index refraction and photorefractive sensitivity, which are very significant for optical data storage. In all experiment, two- wave mixing configuration at 632.8 nm (He- Ne laser) were used. Experimental data f...

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