The invention provides a three-dimensional microscale measuring device and method based on a four-core
fiber grating, and belongs to the technical field of precision instrument manufacturing and measurement. The device comprises a
broadband light source, an
optical spectrum analyzer, an
optical circulator, a control computer, a multi-way
optical switch and an
external reference grating. The multi-way
optical switch is communicated with a four-core
fiber fan-out device through four single mode fibers. One end of a four-core
fiber is connected to the four-core fiber fan-out device. A four-core fiber
grating probe is fixedly installed at the other end of the four-core fiber through a probe clamp holder. The four-core fiber and the four-core fiber grating probe are connected to form a
closed circuit. According to the method, the multi-way
optical switch is controlled by the control computer to switch optical paths, the
optical spectrum analyzer is used for measuring reflectance spectra of the
fiber gratings, and three-dimensional microscale measuring without temperature
coupling is realized by utilizing a differential
data processing algorithm. The three-dimensional microscale measuring device and method based on the four-core fiber grating have the advantages that accuracy is high,
contact force is small, the device and method are not affected by the masking effect, and the service life of the probe is long.