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...

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  In this paper we explain in detail the design of a semiconductor laser coupled with the reflected beams from a grating. Since the beams reflected are diffracted at different angles, only one component of them can be resonated in the cavity. This technique reduces the output frequency of the laser and increases its stability.   Since this system has various applications in the spectroscopy, ga...

nitric oxide (no) is a small molecule synthesized by most of mammalian cells with diverse biological activities including vasodilatation, host defense and wound healing. impaired wound healing is a common occurrence among diabetics and patients receiving glucocorticoid therapy. on the other hand the application of laser in biomedical area have been increased. thus, the current studies were desi...

  A detailed analysis of electron trajectories in a realizable helical wiggler free electron laser with ion channel guiding using electron (single particle dynamics) is presented. Conditions for stability of electron orbit have been investigated, calculations are made to illustrate. Conclusion shows that there are differences stable (unstable) condition(s) electron trajectories between ideal he...

هدف: این مطالعه به منظور بررسی و مقایسه اثر q-switched nd yag laser و erbium laser در درمان ضایعات پیگمانته انجام شده است. روش مطالعه: 116 فرد مبتلا به ضایعات پیگمانته از نوع فرکل و خال وارد مطالعه شدند که 58 مورد با استفاده از q-switched nd yag laser و 58 مورد با لیزر erbium درمان شدند و در نهایت میزان اثربخشی (از بین رفتن کامل ضایعات) در دو گروه تعیین و مقایسه گردید. یافته ها: در این مطالعه...