J. G. Lynn

Direct upper-state pumping of the 2.8 mu m, Er/sup 3+/:YLF laser

Direct resonant pumping of the /sup 4/I/sub 11/2/ upper state of the 2.8- mu m Er/sup 3+/:YLF laser at 0.97 mu m is shown to be more efficient than other pumping schemes which have been used for this transition. Upper-state pumping avoids nonradiative losses arising from phonon and self-quenching decays inherent in other pumping schemes. Efficient performance of the 2.8- mu m laser is maintained on condition that extremely shallow pump absorption is avoided. Reduced efficiency for shallow pump absorption is attributed to upconversion loss arising from high pumping rates. >

High-average-power operation of a Q-switched diode-pumped holmium laser

We have investigated high-peak- and high-average-power operation of diode-pumped, thulium-sensitized, holmium 2.1-microm lasers. Free-running laser powers of 14 W at 29 Hz have been demonstrated with 2.6% electrical efficiency. Q-switched operation produced average powers in excess of 11 W in a burst of short pulses. Preliminary optical parametric oscillator frequency conversion of the holmium laser to 4 microm is also reported.

Power scaling of diode-pumped 2 micron lasers

Summary form only given. We have investigated high peak and average power operation of 2 /spl mu/m lasers as a pump source for parametric frequency conversion. Our goal is to produce a compact, reliable and tunable source of mid-IR radiation. A Tm,Ho:YAG Q-switched laser resonator system was developed to provide this pump source.<<ETX>>

High-power diode-pumped 2-μm lasers

We have investigated diode pumped thulium and holmium YAG lasers. Comparisons of laser performance for several different Tm/Ho concentrations and the results of a prototype Q- switched laser are reported.

Comparative Study of Diode-Pumped Two Micron Laser Materials

We have studied the characteristics of Thulium and Holmium/Thulium YAG lasers using high power laser diode pumping. Measurements of laser performance have been combined with spectroscopic measurements and compared to rate equation models for these materials.

2.8-um Er 3+ :YLiF 4 laser resonantly pumped at 970 nm

The 2.8-micrometers Er3+:YLF 4I11/2yields4I13/2 laser is shown to have higher efficiency for resonant pumping into the 970-nm absorption band than for the 800-nm pump band. The improved efficiency is due to the lower energy of the 970-nm pump radiation, and the avoidance of the self-quenching process 4I9/2+4I15/2yields4I13/2+4I13/2 which partially bypasses the upper laser state for 800-nm pumping. These advantages result from the direct pumping of the 4I11/2 upper laser state in the 970-nm pumping scheme.