Brillouin comb generation in a ring cavity with tellurite single mode fiber

We experimentally demonstrate tunable Brillouin comb generation in a ring cavity composed of a piece of tellurite single mode fiber. The tunable Brillouin comb lines are separated with frequency space of 7.9 GHz, which is equal to the Brillouin frequency shift in the tellurite fiber. Due to the high Brillouin gain coefficient of the tellurite fiber, a tellurite fiber as short as 200 m was inserted into the ring cavity. Cascaded stimulated Brillouin Stokes and anti-Stokes lines are generated in the ring cavity leading to multi-wavelength Brillouin comb generation bi-directionally. By tuning the narrow-linewidth tunable laser, we can tune the Brillouin comb in the wide range of 1533 nm to 1565 nm.