UNLABELLED Cracking of tooth structure is a frequent mechanism of clinical failure necessitating treatment. Some laser conditions, particularly those without sufficient water cooling, may cause surface cracking of dentin. Surface cracks may serve as initiation sites for the onset of catastrophic fracture under mechanical stress, resulting in failure of the dentin. In this study, the hypothesis ...

We established a new diode array pumped Er:Yb:Glass test setup for evaluation of the laser performance and q-switch characteristics of various saturable absorber materials at 1.54um. Pumping distribution and maximum gain was analyzed. Passive q-switched laser operation was demonstrated with both U: CaF2 and Co : MgAl2O4. TEMoo Qswitch pulses with energy of 0.5mJ and pulse width of 10ns was obta...

In this paper, a double-clad Er/Yb fiber laser with self-Q-switched and continuous wave operation depending on the pump power range is experimentally demonstrated. The linear cavity is formed on one side by a pair of cascaded tunable fiber Bragg gratings used for the selection and tuning of the generated laser lines. On the opposite side, a fiber optical loop mirror with high birefringence fibe...

The numerical modeling of actively Q-switched fiber lasers is systematically presented. On the basis of typical Q-switched ytterbium-doped double-clad fiber lasers under forward and backward pump, the dynamic characteristics of pulse energy, pulse width, population inversion, and stored energy at tens-of-kilohertz repetition rates are studied by using the traveling-wave method. The laser perfor...

We report an efficient high-peak-power and high-average-power passively Q-switched ytterbium fiber laser with a Cr(4+):YAG crystal as a saturable absorber in an external-resonator configuration. At an incident pump power of 17.5 W, the passively Q-switched fiber laser produces an average power greater than 6.2 W with a pulse repetition rate of 48 kHz. The output pulses noticeably display a mode...

drives are designed to increase product performance and system efficiency. One such motor type which can benefit from digital control is the switched reluctance (SR) motor. The SR motor brings advantages in both cost and reliability over other types of adjustable speed drives. These include its simple mechanical construction, high efficiency and high power density. On the other hand, large torq...