Laser doide array with narrow linewidth for rubidium vapor laser pumping

Since the Rb D2 absorption linewidth is much narrower than that of commercially available diode lasers, linewidth reduction of diode laser is one of the key technologies in Rb vapor laser. In this paper, a 40 W laser diode array (LDA) with linewidth of 0.14 nm and wavelength of 780 nm was realized through external cavity technology of volume Bragg grating (VBG). By controlling the temperature of the VBG with a thermoelectric cooler (TEC), the central wavelength of the LDA was tunable from 779.39 nm to 780.10 nm (in air). That means the LDA can be used as an efficient pumping source for Rb vapor lasers.