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...

introduction: the unprotected eye is extremely sensitive to laser radiation and can be permanently damaged from direct or reflected beams. the area of the eye damaged by laser energy is dependent upon the wavelength of the incident laser beam, duration of exposure and tissue characteristics. this study aims to investigate the effect of intense green light from doubled frequency neodymium-doped ...

Applications based on the propagation of high power laser radiation through the atmosphere are limited in range and effect, due to weather dependent beam wandering, beam deterioration, and scattering processes. Security and defense related application examples are countermeasures against hostile projectiles and the powering of satellites and aircrafts. For an examination of the correlations bet...

This first stage experiment is a Proof-of-Principle to support our novel vacuum laser acceleration (VLA) theory, published previously. Simulations show that based on current experimental conditions at the Brookhaven National Laboratory Accelerator Test Facility (ATF), an electron beam with initial energy of 15 MeV can get net energy gain from an intense CO2 laser beam. The difference of electro...

In high power solid-state-laser systems, one of the major problems is the thermal effect, which occurs in optically pumped laser materials. Heating of the laser medium causes thermal distortions, leading to degradation of beam quality. The main thermal effects in laser rods are thermally induced birefringence and thermal lensing effects. High efficiency, high power and good output beam quality ...

The laser scalpel and the laser coagulator are representative in laser medicine. However the biostimulative effect of laser with low power is getting the focus of attention, since acceleration of wound healing has been proved by laser radiation. Recently laser acupuncture was initiated as an unique therapeutic application in Europe and China. In Japan the authors have developed YAG laser acupun...

introduction: although dental caries is a preventable disease, it is still common and remains a public health problem. one of the potentially effective preventive measures is the use of lasers. the purpose of this study was to review the studies about use of laser irradiation on the inhibition of carious lesions and the effectiveness of different commercial laser type (nd:yag, co2, and argon). ...

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...

Self-mode-locking is a common way of generating very short laser pulses.12 It occurs when a beam self-focuses and narrows as it passes through a nonlinear intracavity material, thus expanding or contracting at other locations of the laser cavity.3 Since self-focusing is an intensity-dependent process, at any point in the cavity an intense (mode-locked) laser beam has a different size from a wea...