A tuneable, single-mode titanium-doped-sapphire laser source with variable pulse duration in the nanosecond regime

We built and characterized a high-energy, injection-seeded, single-longitudinal-mode pulsed titaniumdoped- sapphire laser with tuneable wavelength in the near-infrared and variable pulse temporal duration in the nanosecond regime. We show experimentally how the pulse duration can be easily varied either by changing the cavity length or by changing the pump energy. We successfully interpreted these results on the basis of a theoretical model which treats the operation of this type of laser as a gain-switching technique. Also, as far as the stabilization of the laser cavity, compared to the traditional techniques we employed a novel simplified solution involving the use of an avalanche photodiode.