The invention provides a polarization-maintaining flat
optical fiber coupling ball microscale sensor based on polarization state detection and belongs to the technology of manufacturing and measurement of precise instruments. The polarization-maintaining flat
optical fiber coupling ball microscale sensor comprises a
laser, a semi-transparent semi-reflective
prism, a quarter
lambda wave plate, a probe, a polarization state detection device A, a polarization state detection device B and a computer, wherein the probe is composed of a flat
package layer polarization-maintaining
optical fiber and a
coupling ball, and the
laser, the semi-transparent semi-reflective
prism, the quarter
lambda wave plate and the probe are arranged in sequence. Emergent light of the
laser is reflected and transmitted by the semi-transparent semi-reflective
prism, and reflected light enters the polarization state detection device A; transmission light enters the probe, reverse transmission of a transmission
light beam is achieved after the transmission
light beam passes through the coupling ball, the transmission light exits from the probe, and emergent light passes through the quarter
lambda wave plate, is reflected by the semi-transparent semi-reflective prism again and then enters the polarization state detection device B. When the difference value between the polarization state detected by the polarization state detection device B and the polarization state detected by the polarization state detection device A is changed, it can be determined that the probe is in contact with a detected hole. The polarization-maintaining flat
optical fiber coupling ball microscale sensor is high in precision and high in speed.