Core area scaling of Nd:Al-doped silica depressed clad hollow optical fiber and Q-switched laser operation at 0.9 microm.
We demonstrate a Q-switched, cladding-pumped, Nd:Al-doped silica depressed clad hollow optical fiber (DCHOF) laser, which generated up to 133 microJ of pulse energy at a repetition rate of 5 kHz and 0.9 W of average output power at a high repetition rate (>20 kHz) in a diffraction-limited beam (M(2)=1.08) at 927 nm. The laser was tunable from 919 to 935 nm. This result shows the potential of the DCHOF structure for the suppression of unwanted long-wavelength radiation in large-area cores suitable for high-power Q-switched laser operation.