Lasers are essentially chaotic system. However, semiconductor lasers are classified into stable class B lasers. Meanwhile, they are easily destabilized by external perturbations (introduction of extra degree of freedom). We discuss chaos in lasers and also instability and chaos in semiconductor lasers. Recently, new semiconductor lasers with extra device structures have been developed and they ...

introduction: ablative and nonablative lasers have been used to treat melasma. we aimed to assess and compare the combining q-switched nd:yag laser (qsnyl) and fractional erbium:yag laser (feyl) with qsnyl alone in treatment of melasma. methods: this randomized controlled clinical trial was performed in our research center during 2013-2014. women with melasma and without a history of keloid for...

objective: the aim of the present study was to compare the performance of laser fluorescence (lf) method with other conventional diagnostic techniques in detection of small occlusal caries in permanent teeth. materials and methods: prior to this in vitro diagnostic study, a pilot study assessed intra- examiner reliability and reproducibility. the occlusal surfaces of 90 extracted human premolar...

the laser technology offers a wide range of uses in dentistry with certain advantages to the general dental practitioner like bloodless surgery, minimal post-operative pain, reduction of operative time and high patient acceptance. patient acceptance has also been demonstrated in various studies. apart of these major advantages, safety regarding the use of lasers cannot be neglected and has beco...

Terminology Introduction to Electromagnetic Radiation Physical Properties of Electromagnetic Radiation History of Electromagnetic Radiation Physiological Effects of Electromagnetic Radiation Introduction to Lasers and Light Brief History of Lasers and Light Physical Properties of Lasers and Light Effects of Lasers and Light Promote Adenosine Triphosphate Production Promote Collagen Production M...

it is of utmost importance to make children interested in and willing to use dental services in order to prevent and treat oral diseases. therefore, pediatric dental practitioners need to learn new technologies such as lasers, in addition to basic principles. lasers have opened new horizons in the treatment of both soft and hard oral tissue problems in children. the present article describes ap...

Low level lasers, cold or soft lasers: These lasers do not produce thermal effects on tissues and induce photoreactions in cells through light stimulation which is called photobiostimulation. Power of these lasers is usually under 250mW. The main point differentiating low level lasers and high power ones is the activation of photochemical reactions without heat formation. The most important fac...

laser-tissue interaction is of great interest due to its significant application in biomedical optics in both diagnostic and treatment purposes. major aspects of the laser-tissue interaction which has to be considered in biomedical studies are the thermal properties of the tissue and the thermal changes caused by the interaction of light and tissue. in this review paper the effects of light on ...

Microchip lasers are a rich family of solid-state lasers defined by their small size, robust integration, reliability, and potential for low-cost mass production. Continuous-wave microchip lasers cover a wide range of wavelengths, often operate single frequency in a near-ideal mode, and can provide a modest amount of tunability. Q-switched microchip lasers provide the shortest output pulses of ...