Observation of direction instability in a fiber ring laser

Abstract

We report on the observation of a new phenomenon occurring in a fiber ring laser. This phenomenon is about the transition from an initially bidirectional emission of a reciprocal fiber ring laser to a unidirectional emission at a certain pump power threshold. In addition, the final direction is not predefined but appears to be randomly chosen every time the threshold is exceeded. Therefore, we term this new phenomenon direction instability. Furthermore, we provide a first discussion of how the instability threshold is influenced by the length and the loss of the cavity. We show that the threshold follows a power times length scaling, indicating a nonlinear origin.

Brillouin-like effects in rare-earth-doped bi-directional optical fiber amplifiers

“…The PIDG analog of the forward Brillouin scattering in optical fibers [66][67][68][69][70][71] could be of particular interest for further studies due to its enormous potential for practical applications in soliton fiber lasers as the method enabling the stabilization of harmonically mode-locked laser operation and super-mode noise reduction [72][73][74][75][76][77] . New mechanisms are important as well for designers of the Brillouin and random fiber lasers [78][79][80][81][82][83][84][85][86][87][88][89][90][91][92][93] demanded in many applications in microwave photonics, data centers and atomic clocks. Translating the fiber system design to integrated photonics could dramatically reduce the footprint for many these applications 94-97 .…”

From instable directional switching to controlled unidirectional operation in a nonlinear fiber ring laser

“…The fiber ring laser is rather similar to the initial one presented in 1 . It is comprised of the pump-signal-combiner, the active fiber Nufern SM-YDF-5/130, the passive fiber Corning HI1060 and now two output couplers enclosing the passive fiber for a closer look into its internal events (Fig.…”

“…In our last publication we demonstrated a unique phenomenon, where a simple reciprocal fiber ring laser without any directional constraints switched reliably from bidirectional to unidirectional operation above a certain pump power threshold 1 . From an application perspective it appears very attractive to get a ring laser operating in a single direction without the need of a dedicated, optically non-reciprocal element or layout like e.g.…”

“…We shortly summarize the most relevant facts from our last publication 1 , which is to the best of our knowledge the first publication covering this topic. The setup in question was a simple cladding-pumped fiber ring laser consisting of a pump signal combiner, 6 m Yb-doped active fiber (Nufern SM-YDF-5/130), 1 km single-mode fiber (Corning HI1060) and a 0.01% tap coupler for monitoring the circulating powers and spectra.…”