introduction: periodontitis is an inflammatory periodontal disease that leads to tooth loss. recently laser has been introduced as an alternative treatment for periodontitis. the aim of the present study was to compare the effect of erbium-doped yttrium aluminum garnet (er:yag) laser with ultrasonic scaler in patients with moderate chronic periodontitis. methods: in this randomized single-blind...

introduction: the main purpose of the present study was to describe the ultra structural changes which happened after treatment of the root surfaces with ultrasonic and hand devices followed by erbium-doped yttrium aluminum garnet (er:yag) laser irradiation. methods: sixty single-rooted maxillary and mandibular teeth which had been extracted due to periodontal problems were collected. crown and...

A drift free synchronization distribution system with femtosecond accuracy is of great interest for free-electronlasers such as FLASH or the European XFEL. Stability at that level can be reached by distributing laser pulses from a mode-locked erbium-doped fiber laser master oscillator over actively optical-length stabilized fiber-links. In this paper we present a prototype of a fiber-link stabi...

Introduction Soft tissue surgical lasers have many advantages over traditional scalpel surgery, cryosurgery, and electrosurgery. However, not all lasers are equally efficient at both cutting the soft tissue, coagulating, and hemostasis because light absorption in the soft tissue varies with wavelength.1-3 As illustrated in Figure 1, some dental laser wavelengths (around 1,000 nm, such as diodes...

We report on the fabrication and characterization of a distributed feedback channel waveguide laser in erbium-doped aluminium oxide on a standard thermally oxidized silicon substrate. Holographically-written surface-relief Bragg gratings have been integrated with the aluminium oxide waveguides via reactive ion etching of a silicon dioxide overlay film. The laser operates at a wavelength of 1545...

A C- plus L-band fiber ring laser with wide wavelength tunability and single-longitudinal-mode oscillation is proposed and demonstrated experimentally. A saturable-absorber-based autotracking filter, consisted of an unpumped erbium-doped fiber (EDF) and an optical reflected mirror (ORM), is employed to provide fine mode restriction and guarantee the single-frequency operation. Output power of >...

New theory on measuring gain and index changes in femtosecond pump probe studies suggests a spectral artifact is present which may have obscured the ultrafast response in previous studies of InGaAsP laser diode amplifiers. A femtosecond heterodyne pump-probe technique is implemented using an Erbium-doped stretched-pulse modelocked fiber laser centered at 1.55 gm and used to obtain simultaneous ...