Advanced waveguide lasers fabricated by femtosecond laser writing in an Er:Yb-doped phosphate glass

摘要

Recently, great effort has been devoted to waveguide lasers, because of their inherent simplicity with respect to fiber lasers. Actually, due to their compactness, such lasers are expected to achieve a higher temporal coherence, making them attracting for fiber optical reflectometry, distribute sensing, and range finding applications. Furthermore, the availablity of fast saturable absorbers based on carbon nanotubes allows for a cheap and reliable implementation of the passive mode-locking technique with the potential for generating high repetition rate pulse trains. Such lasers will provide low-noise and inexpensive pulsed sources for applications in optical communications, optically sampled analog-to-digital converters, and spectral line-by-line pulse shaping. We report here on advanced waveguide lasers, operating both in continuous wave and pulsed regimes, based on active waveguides fabricated by femtosecond laser writing in a phosphate glass substrate. A single longitudinal mode waveguide laser providing more than 50 mW with 21% slope efficiency was demonstrated. Furthermore, by combining a high gain waveguide and an innovated fiber-pigtailed saturable absorber based on carbon nanotubes, a mode-locked ring laser providing transform limited 1.6-ps pulses was also demonstrated.