Influence of Cavity Loss Upon Performance of Q-Switched Erbium-Doped Fiber Laser
Performance of an actively Q-switched erbium-doped fiber laser in function of intracavity loss is discussed. We show experimentally and theoretically (employing a distributed model that takes into account two contra-propagating laser waves) that the laser performance strongly depends on the intracavity loss of different kinds. We reveal in particular that the dominant source of smaller than expected pulse energy is the loss via excited-state absorption, inherent in erbium-doped fibers. We also discuss the other important processes involved in active Q-switching, such as passive losses and residual active fiber charge, the impact of which is clarified by a straightforward comparison of the m…
Smart Q-switching for single-pulse generation in an erbium-doped fiber laser
In this paper, we report an active Q-switching of an erbium-doped fiber laser with special modulation functions and novel laser geometry. We experimentally demonstrate that using such a smart Q-switch approach, Q-switch ripple-free pulses with Gaussian-like shape and 17.3 ns width can be easily obtained. The idea behind the smart Q-switch is to suppress one of two laser waves contra-propagating along the fiber cavity, which arises after Q-cell opening, and to eliminate the minor sub-pulses.