Mode-controllable coherent feedback optical fiber random laser device

The invention provides a mode-controllable coherent feedback optical fiber random laser device. The mode-controllable coherent feedback optical fiber random laser device comprises a pump light source, a wavelength division multiplexer, an active optical fiber, a coupler, a control light source and a collimator. Compared with the prior art, the mode-controllable coherent feedback optical fiber random laser device has the advantages that the control light source generates control light, and the collimator connected with the control light source receives the control light, generates collimated light beams, and irradiates one of resonant cavities in the light transmission direction perpendicular to a fiber Bragg grating string to increase light gain corresponding to a resonance mode, so that interference among random lasers in different resonance modes is reduced, and output stability and power efficiency are improved.