Fabrication method of ultra-small gradient-index fiber probe

Fabrication method and device of ultra-small gradient-index （GRIN） fiber probe were investigated in order to explore the development of ultra-small probes for optical coherence tomography （OCT） imaging. The beam- expanding effect of no-core fiber （NCF） and the focusing properties of the GRIN fiber lens were analyzed based on the model of GRIN fiber probe consisting of single-mode fiber （SMF）, NCF and GRIN fiber lens. A stereo micro- scope based system was developed to fabricate the GRIN fiber probe. A fiber fusion splicer and an ultrasonic cleaver were used to weld and cut the fiber respectively. A con- focal microscopy was used to measure the dimensions of probe components. The results show that the sizes of probe components developed are at the level of millimeter. Therefore, the proposed experimental system meets the fabrication requirements of an ultra-small self-focusing GRIN fiber probe. This shows that this fabrication device and method can be employed in the fabrication of ultra- small self-focusing GRIN fiber probe and applied in the study of miniaturized optical probes and OCT systems.