Diode pumped rubidium vapor laser with linearly polarized fundamental mode output

A Littrow external cavity was built to narrow the spectral linewidth of a diode laser to 0.16 nm by using a 2400 line/mm plane grating, with the center wavelength of the laser tunable. The laser was used as the pump source of the rubidium vapor laser. A chopper was employed to change the continuous laser to pulsed laser with the pulse width of 1 ms and the repetition rate of 100 Hz, then the laser was focused to a Rb vapor cell with the length of 8 mm which was filled with Methane at the pressure of 79 kPa. With the maximum peak power of the pulsed laser injected into the Rb cell is 1.84 W and the temperature of the cell is controlled at about 125 ℃, the linearly polarized fundamental mode Rb laser with the peak power of 17.5 mW is obtained.