Theoretical study on Brillouin fiber laser sensor based on white light cavity.

We present and theoretically study a superluminal fiber laser based super-sensor employing Brillouin gain. The white light cavity condition is attained by introducing a phase shift component comprising an additional ring or Fabry-Perot cavity into the main cavity. By adjusting the parameters of the laser cavity and those of the phase component it is possible to attain sensitivity enhancement of many orders of magnitude compared to that of conventional laser sensors. The tradeoffs between the attainable sensitivity enhancement, the cavity dimensions and the impact of the cavity roundtrip loss are studied in details, providing a set of design rules for the optimization of the super-sensor.