The invention relates to the technical field of
optical fiber sensing and
optical fiber device manufacturing, and discloses a
femtosecond laser-inscribing polarization-maintaining
fiber grating method and
system for vector sensing, and the method comprises the following steps: obtaining a stress region image of a polarization-maintaining
fiber through a
CCD camera, recognizing the slow axis direction of the
fiber through
image processing, rotating the fiber, and obtaining the stress region image of the polarization-maintaining fiber; an included angle of 45 degrees is formed between the slow axis direction and a preset incident plane of the
femtosecond laser; calculating a conjugate phase of
wavefront aberration generated when
femtosecond laser penetrates through a
fiber coating layer and a cladding and is focused to a fiber core, and generating a
phase diagram for loading a
spatial light modulator; after being modulated by the
spatial light modulator, a
light beam emitted by the femtosecond laser enters and is focused on the fiber core along the direction of an included angle of 45 degrees, and a
grating structure is formed by combining axial scanning and inscribing. Accurate automatic alignment in the fast and slow axis direction and
active compensation of transmission aberration are achieved,
refractive index modulation
birefringence forming a specific included angle with the inherent
birefringence axis of the
optical fiber can be effectively induced, and therefore the polarization-maintaining fiber
grating with the highly controllable
reflection spectrum and the asymmetric double-peak characteristic is engraved.