Panasonic threaded type fiber is a standard fiber which is mounted using nuts. It has reasonable pricing while drastically improving flexing performance. With the lens installable type, long distance sensing and microscopic object sensing is possible by installing a lens. A protective tube and a sturdy stainless jacket type that prevents disconnection are also prepared. The beam axis deviation of each unit is kept within ±3° and the beam axis centering accuracy is kept within ±150 μm. High precision polishing is accomplished by using the PCTC polishing technique. The specularity of the end face of the fiber is 5 times greater. It is a coaxial fiber that encloses the circumference of the emitter fiber at the center with the receiver fiber. This is suitable for high-precision positioning. It can perform sensing without affecting the approach direction of the work.