Non-stationary Characteristics of the instability in a Single-mode Laser with Fiber Feedback

Chaotic bursts are observed in a single-mode microchip Nd:YVO$_4$ laser with fiber feedback. The physical characteristic of the instability is a random switching between two different dynamical states, i.e., the noise-driven relaxation oscillation and the chaotic spiking oscillation. As the feedback strength varied, transition which features the strong interplay between two states exhibits and the dynamical switching is found to be non-stationary at the transition.