today laser has a lot of usage in medicine and dentistry. in the field of dentistry, laser is used in soft tissue surgery, sterilization of canals (in root canal therapy) and in restorative dentistry laser is used for cavity preparation, caries removal, sealing the grooves (in preventive dentistry), etching enamel and dentin, composite polymerization and removal of tooth sensitivity. the use of...

Diode laser-pumped solid-state lasers are efficient, compact, all solid-state sources of coherent optical radiation. Major advances in solid-state laser technology have historically been preceded by advances in pumping technology. The helical flash lamps used to pump early ruby lasers were superseded by the linear flash lamp and arc lamp now used to pump neodymium-doped yttrium-aluminum-garnet ...

We have generated picosecond opfic1 pulses with very pure spectral characteristics using semiconductor lasers with monolithic cavities. Fx repetition rates less than 10 GHz, gain-switching of DFB lasers with quantum well loss-gratings is usul. Monolithic colliding pulse mode-locked semiconductor lasers are used to generate short pulses with repetition rate up to 350GHz.

Beating noise in narrow-linewidth erbium-doped fiber ring lasers puts severe limitations on applications of the lasers. We demonstrate the suppression of beating noise in fiber ring lasers by using a semiconductor optical amplifier in the laser cavity, which acts as a high-pass filter. Two different ring structures are presented as examples to demonstrate this beating noise suppression.

Injection-Locked Vertical Cavity Lasers exhibit drastically enhanced performance. The 3-dB bandwidth can be increased up to 40 GHz, due to a resonance frequency enhancement. Such VCSELs may play a role in future optical interconnects. c © 2007 Optical Society of America OCIS codes: (140.3520) Injection-locked lasers; (250.7260) Vertical cavity surface emitting lasers

This paper presents two extended cavity diode laser tuning schemes, implemented using blue diode lasers, the first allows long mode-hop free tuning ranges (>110 GHz), whereas the second allows very high scan rates (>10 kHz). ©2005 Optical Society of America OCIS codes: (140.3600) Lasers, tunable; (140.2020) Diode lasers; (120.4570) Optical design of instruments

We observed modulated oscillations in lasers of up to 130 GHz by conducting frequency domain measurements on photonic crystal lasers with built-in saturable absorbers. This is an example of how the small volumes of photonic crystal lasers lead to increases in the internal modulation frequencies and enables dramatic improvements of the laser modulation rate. © 2004 American Institute of Physics....

Experimental investigations of synchronization and anti-synchronization of optically coupled semiconductor lasers with external cavities are presented. Both lasers show chaotic lowfrequency intensity fluctuations that are (anti-) synchronized due to optical coupling by light injection. For uni-directional coupling response lasers with and without external cavity are considered. In the case of b...

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...

Device-performances of 3.7 THz indirect-pumping quantumcascade lasers are demonstrated in an InGaAs/InAlAs material system grown by metal-organic vapor-phase epitaxy. The lasers show a low threshold-current-density of ~420 A/cm and a peak output power of ~8 mW at 7 K, no sign of parasitic currents with recourse to well-designed coupled-well injectors in the indirect pump scheme, and a maximum o...