introduction: periodontal diseases are considered as some of the most common reasons of teeth loss, which occur due to the aggregation of microbial plaque and other precipitations on the dental surfaces . in this study, the scaling effect using manual tools, ultrasonic machine and erbium-doped yttrium aluminum garnet (er:yag)laser on the connection of the human gums connective tissue cells on t...

BACKGROUND Auditory neural stimulation with pulsed infrared radiation has been proposed as an alternative method to activate the auditory nerves in vivo. Infrared wavelengths from 1800-2150 nm with high water absorption were mainly selected in previous studies. However, few researchers have used the short-wavelength infrared (SWIR) for auditory nerve stimulation and limited pulse parameters var...

Second harmonic cross correlation functions of a pulse with its near neighbor have been studied in a synchronously pumped cw dye laser. Measurements were made both as a function of dye laser cavity length mismatch and the number of cavity round trips separating the correlated pulses. The pulse envelope is found to have a characteristic interpulse frequency determined by the pump laser, whereas ...

Short pulsed laser is preferred to avoid the thermal damage in processing the heat sensitive material, such as carbon fiber reinforced plastic (CFRP). In this paper, a numerical model capturing both the material ablation and polymer matrix pyrolysis processes in pulsed laser processing is established. The effect of laser pulse length from ns order to μs order is studied. It was found that with ...

We present an experimental and numerical study of electron emission from a sharp tungsten tip triggered by sub-8 femtosecond low power laser pulses. This process is non-linear in the laser electric field, and the non-linearity can be tuned via the DC voltage applied to the tip. Numerical simulations of this system show that electron emission takes place within less than one optical period of th...

Recently, interest has developed in pulsed heating effects on a copper surface[1]. Pulsed heating is one of the limits on the gradient of a structure based linac. The heat generated by an intense RF pulse on the metal surface can result in hundreds of degrees of temperature rise at 1 GeV/m. After a certain number of cycles, the metal may crack due to thermal fatigue and the surface properties m...

High power single mode fiber lasers are an excellent tool for micro cutting applications. In order to manage the heat input into the material most micro cutting applications require pulsed operation of the laser. Temporal pulse shaping is a proven and enabling technology for many laser welding applications with flash lamp pumped lasers where typical pulse lengths are in the order of 0.1 to 10 m...

PURPOSE The present study was performed to evaluate the effect of erbium:yttrium-aluminium-garnet (Er:YAG) laser irradiation on the change of hydroxyapatite (HA)-coated implant surface microstructure according to the laser energy and the application time. METHODS The implant surface was irradiated by Er:YAG laser under combination condition using the laser energy of 100 mJ/pulse, 140 mJ/pulse...

Progress in ultrafast science and technology has pushed the temporal resolution to subfemtosecond and attosecond region (Kienberger el at., 2002; Fleischer & Moiseyev, 2006; Corkum & Krausz, 2007; Goulielmakis el at., 2007) and technology exploration in ultrashort pulse generation has made it possible to equip femtosecond lasers that are only a few cycles in duration (Xu el at., 1996; Shirakawa...