LiF: F(2)- as a high repetition rate Ng: YAG laser passive modulator.
30-pps 30-mJ 10-ns FWHM pulses have been obtained in Nd:YAG laser systems with LiF crystal containing F(2)- color centers as the passive Q-Switch modulator. The saturation level of F(2)- color centers in the host crystal and the annealing phenomena of LiF: F(2)-(2) crystal were investigated. These observations make this room temperature stable color center crystal superb as a high power, high repetition rate neodymium laser passive modulator.
Passively Q-switched transverse-diode-pumped Nd(3+):YLF laser oscillator.
The design and performance of a diode-pumped Nd3+:YLF laser oscillator is described. A simple transverse-pump geometry in which a lensing duct efficiently couples the two-dimensional diode-pump array radiation to the YLF rod is employed. Using a color-center LiF crystal as a passive Q switch, we have produced burst-mode pulse trains that have a total energy of 115 mJ at a 30-Hz pulse-repetition frequency. The Q-switched pulse-train energy is 71% of the optimized free-lasing pulse energy, which is 163 mJ. Using an unstable cavity with a graded-reflectivity output coupler, we have generated Q-switched pulses that have 12-ns duration and near-diffraction-limited spatial profiles.
Anomalous Annealing Behavior of Arsenic Implanted Silicon as a Function of Dose and Energy
Anomalous annealing behavior of damage in As implanted Si has been investigated by channeling effect measurements. Room temperature As implants with doses from 1014 to 2 × 1016cm-2 at energies ranging from 50 to 250 keV into Si were annealed over the range of 600°C to 1100°C. Anneal temperatures ≥ 950°C reduce the disorder for ion doses of 0.5 to 1 × 1016 cm-2 at energies between 50 and 250 keV. Anomalously high residual disorder was found for the intermediate doses of 2 × 1014 to 2 × 10/cm2 implanted above 100 keV. For this intermediate dose, annealing of implants performed at liquid nitrogen temperatures did not show significant reduction in this damage. However implants at 200° to 300°C indicate a lower amount of damage compared to the room temperature implants.