Self-heating leads to a temperature rise of the laser diode and limits the output power and efficiency due to increased loss and decreased differential gain. To control device self-heating, it is required to design the laser structure with a low optical loss, while the heat flux must spread out of the device efficiently. In this study, a new asymmetric waveguide design is proposed and th...

Introduction: The aim of the present study was to determine burn intensity in retinal laser photocoagulation based on laser parameters; wavelength, power, beam size and pulse duration, using Optical Coherence Tomography (OCT), fundus camera, physical eye model and computer simulation in a clinical study.Materials and Methods: Participants were 10 adult patients between 50-80 years with prolifer...

Background: There is a large variety of therapeutic agents for the treatment of vitiligo, but it still remains a challenge. Narrow-band UVB phototherapy and 308-nm excimer laser have been shown to be safe and effective for the treatment of vitiligo. Topical calcipotriol has recently been reported to enhance the efficacy of phototherapy, especially 8-methoxypsoralen plus UVA (PUVA). The goal of ...

In a ring laser gyroscope, due to the rotation and the Sagnac effect, a phase difference between the two counter-propagating beams is generated. In this device, the higher phase difference between these two beams causes the better the interference pattern detection, and thus the sensitivity is increased. In this paper, the effect of inserting a dielectric-graphene photonic crystal inside a ring...

A quantum theory of a two and three-level laser with injected atomic coherence is developed by using a density operator method, to the best of our knowledge, for the first time. The initial atomic coherence plays an essential role. At steady state, the equation of motion for the density operator yields to exhibit laser without inversion and a phase locking but no threshold for the laser fie...

Since 1976, Shooting was include in Paralympics sport mach’s to establish same target conditions for different types of handicapped people, it is essential design a system of “laser target controls”. In this study, a laser target controller is designed by determinable of wave length of laser accuracy then, by using parameters, performance and ever redacting, theses wave length import as inp...

introduction: the aim of this study was to evaluate the effect of dental surface treatment with erbium-doped yttrium aluminum garnet(er: yag), neodymium-doped yttrium aluminium garnet(nd: yag) and carbon dioxide laser  (co 2 ) lasers and sodium ascorbate to recently home bleached enamel by scanning electron microscope (sem). methods: thirty extracted human third molars were selected for this in...

Introduction: By introducing of laser systems and their continuous development, a new chapter of laser systems applications in a variety fields including research and clinical science in addition to the therapeutic, diagnostic applications were available for medical professionals in various fields. Most lasers emit radiation with intrinsic probable risks where in laser-tissue i...