A titanium-doped-sapphire laser source with tuneable frequency, single-mode emission and adjustable pulse duration

We present a laser source with several desirable characteristics, such as tunable wavelength in the near infrared, singlelongitudinalmode emission and variable pulse temporal duration in the nanosecond regime. The laser is based on an injectionseeded Titaniumdopedsapphire ring cavity. Our experiments show how the pulse duration can be varied in a controllable fashion either by changing the cavity length or by changing the pump energy. We present a theoretical model which successfully reproduces the experimental results by treating the operation of this type of laser as a gainswitching technique. As far as the stabilization of the laser cavity, we also present a novel solution involving the use of an avalanche photodiode