Fig. 1. Schematic of glass-blown Rb cell

Fig. 2. Transmittance versus wavelength in the area of steam chamber

Fig. 3. Experimental setup

Fig. 4. (a) Schematic of laser transmission of resonant cavity A and (b) picture of spots

Fig. 5. (a) Schematic of laser transmission of resonant cavity B and (b) picture of spots

Fig. 6. (a) Schematic of experimental setup; (b) image taken by camera 1; (c) image taken by camera 2

Fig. 7. Output power of cavity A as a function of pump power

Fig. 8. Laser power curve with output coupling mirror

Fig. 9. Theoretically calculated threshold pump power density at different output coupling rates