A fiber pigtail is the end of a fiber optic connector, usually a length of about 10 cm of fiber bundle with a fiber connector attached at one end and a bare fiber core at the other. It is commonly used for the connection of optical devices such as optical modules, optical switches, optical amplifiers, as well as fiber optic sensors, fiber optic temperature measurement and other application scenarios. The fabrication of fiber optic pigtails requires high precision fiber optic fusion splicing technology to ensure the quality and stability of optical signal transmission.