Self mixing interference measurement system of a fiber ring laser with ultra narrow linewidth.
A novel device for self mixing interference measurement based on the fiber ring laser with ultra narrow linewidth was investigated for the first time. In order to achieve requirement of our measurement system, a saturable absorber which consists of a segment un pumped erbium doped fiber and a fiber Bragg grating is employed to provide a fine mode selection and guarantee the ultra narrow linewidth operation. Results demonstrate that the signal to noise ratio of the self mixing interference signal could be enhanced from 18.01 dB to 38.35 dB by inserting a saturable absorber in the laser cavity. It is in good agreement with the theoretical analysis and proved potential using in self mixing interference measurement system for high sensitivity and remote measurement.
Optics express