28W average power hydrocarbon-free rubidium diode pumped alkali laser.

We present experimental results for a high-power diode pumped hydrocarbon-free rubidium laser with a scalable architecture. The laser consists of a liquid cooled, copper waveguide which serves to both guide the pump light and to provide a thermally conductive surface near the gain volume to remove heat. A laser diode stack, with a linewidth narrowed to approximately 0.35 nm with volume bragg gratings, is used to pump the cell. We have achieved 24W average power output using 4 atmospheres of naturally occurring helium ((4)He) as the buffer gas and 28W using 2.8 atmospheres of (3)He.

Multimode-diode-pumped gas (alkali-vapor) laser.

We report what we believe to be the first demonstration of a multimode-diode-pumped gas laser: Rb vapor operating on the 795 nm D1 resonance transition. Peak output of approximately 1 W was obtained using a volume-Bragg-grating stabilized pump diode array. The laser's output radiance exceeded the pump radiance by a factor greater than 2000. Power scaling (by pumping with larger diode arrays) is therefore possible.

Laser activity at 1.18, 1.07, and 0.97 microm in the low-phonon-energy hosts KPb2Br5 and RbPb2Br5 doped with Nd3+.

For the first time to the authors' knowledge, laser activity has been achieved in low-phonon-energy, moisture-resistant bromide host crystals, neodymium-doped potassium lead bromide (Nd3+:KPb2Br5) and rubidium lead bromide (Nd3+:RbPb2Br5; RPB). Laser activity at 1.07 microm was observed for both crystalline materials. Laser operation at the new wavelengths 1.18 and 0.97 microm that resulted from the 4F5/2 + 2H9/2 - 4IJ transitions (J=13/2 and J=11/2) in Nd:RPB was achieved in a solid-state laser material. Rare-earth-doped MPb2Br5 (M=K, Rb) is a promising candidate for long-wavelength infrared applications because of its low phonon frequencies and other favorable features. In principle, Nd3+:MPb2Br5 has high potential for laser operation at new wavelengths as well as for the achievement of short-wavelength lasing as a result of upconversion.

Resonance transition 795-nm rubidium laser.

Population inversion of the 2P 1/2 and 2S 1/2 levels and continuous-wave, three-level laser oscillation at 795 nm on the D1 transition of the rubidium atom has been demonstrated. Using a titanium sapphire laser as a pump source, we obtained a slope power efficiency of 54% relative to absorbed pump power, consistent with homogeneous broadening of the rubidium pump and laser transitions. The end-pumped rubidium laser performance was well described by use of literature spectroscopic and kinetic data in a model that takes into account ground-level depletion and a pump spectral bandwidth that is substantially larger than the collisionally broadened pump transition spectral width.