Micro-scale measuring device and method based on four-core conical phase-shifted fiber bragg grating

The invention discloses a micro-scale measurement device and method based on a four-core conical phase-shifted fiber grating, and belongs to the technical field of precise instrument manufacturing and measurement. The device comprises a broadband light source, a spectral analysis device, an optical circulator, a control computer, a multi-path optical switch and an external reference grating, four single-mode optical fibers are respectively communicated with a four-core conical phase shift fiber grating probe tail fiber, and the surface of a probe spherical tip is coated with a light absorption material layer; according to the method, the control computer controls the multi-path optical switch to switch optical paths, the spectrum analysis device is used for measuring reflection spectrums of the fiber bragg gratings respectively, and three-dimensional micro-scale measurement without temperature coupling is achieved through a differential data processing algorithm. The method has the characteristics that the me