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As a potential high-energy laser, diode pumped metastable rare gas laser (DPRGL) and diode pumped alkali metal vapor laser (DPAL) have drawn attention worldwide. By using chemically inert metastable rare gas instead of aggressive alkali metal vapor as the active medium, DPRGL has overcome a major problem in DPAL that active medium would react with hydrocarbons and chamber windows. Though one of the advantages of DPRGL is that it can convert diode laser (pumping laser) into laser with high output power and excellent beam quality, efficient pumping of DPRGL requires high pumping intensity and narrow linewidth. By applying narrow bandwidth filters and external optical reflectors, the broad spectra linewidth of diode lasers can be narrowed. Development of volume Bragg grating provides a more convenient and efficient way of linewidth narrowing where VBG is applied as both optical filter and output coupler. In this program, an external cavity diode laser stack (ECDL) coupled with a reflective volume Bragg grating for metastable rare gas laser pumping is presented. The maximum output power of 130 W with 78 pm (FWHM) linewidth was realized. Higher output power can be achieved by vertically increasing the number of laser bars in the diode laser stack. A tuning range of 230 pm was measured which is sufficient for DPRGL pumping. The stability of output wavelength in long-time operation was evaluated by a 5-h test run where wavelength shifted ±7 nm. Total losses caused by passive optical elements, absorptions, etc. do not exceed 14 %. Performance of this narrow-linewidth diode laser stack as pumping source of DPRGL was furtherly examined by transverse pumping of metastable argon laser where the oscillation of metastable argon laser and absorption of pumping laser were detected by photon diode and spectrometer respectively
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