108 W Diode Pumped Rubidium Vapor Laser with Brewster Angle Structure

We have demonstrated a high-power diode pumped rubidium laser with 108W output power. In order to obtain high efficiency diode pumped alkali metal vapor laser, a gain cell with Brewster angle structure is used. The one-way transmittance of the laser in P-polarization is 97%. A gain cell with length of 8 mm is used. It is filled with alkali metal rubidium vapor as gain medium and 600 torr methane as buffer gas. A 295W diode laser with central wavelength of 780 nm and linewidth of 0.2 nm is used as the pump source. In order to reduce the thermal effect of gain cell, a chopper is used to convert the continuous pump laser to pulse output with pulse width of 1.53 ms with repetition frequency of 15 Hz and duty ratio of 2.3%. 108 W peak power of the 795 nm Rb laser was obtained when the temperature of the vapor cell was 160°C and the reflectivity of output coupler was 24%. The optical-optical efficiency was about 36.6% and the slope efficiency was 47.5%.