The invention provides a method and a device for generating weak polarization coupling points with controllable strengths in a polarization maintaining optical fiber of ultraviolet exposure. By adjusting the exposure angle of ultraviolet, the length of an exposure fiber and the refractive rate modulation depth, non-symmetrical refractive rate modulation of the polarization maintaining optical fiber is achieved, so weak polarization coupling points with controllable strengths are generated. The device comprises a KrF laser, a polarization maintaining optical fiber, a rotary fiber function clamp and a fiber feature shaft monitoring device. The method and the device are characterized in that through the weak polarization coupling points with controllable strengths, light loss caused by coupling can be reduced; signal interference between interferometers is reduced; simultaneous effective detection of multiple coupling points is achieved; by use of the weak polarization coupling points, cascading interferometers can be achieved; by writing optical grating in the polarization maintaining optical fiber and generating weak polarization coupling, construction of a cascading polarization maintaining optical fiber optical grating and construction of an optical fiber interferometer reusable multifunctional sensor network based on the generated polarization coupling points are facilitated.
Method and device for generating weak polarization coupling points with controllable strengths in polarization maintaining optical fiber of ultraviolet exposure