PHOTONIC CRYSTAL FIBER AND LASER PROCESSING MACHINE

摘要

PPROBLEM TO BE SOLVED: To make the NA of an emitting tip small, without using a lens, and to reduce the number of parts of a laser processing machine or the like for a photonic crystal fiber having a small numerical aperture at the emitting side. PSOLUTION: The NA at an emitting tip 10b is made small because small holes 13 of the multi-hole section which covers around a core 11 are formed so that the hole diameters are made smaller toward the emitting tips in a tapered manner. More specifically, the length of tapered sections 14 which are the region where the small hole diameters are changed is made equal to or longer than 200m, the characteristics of the light beams actually, propagated in the fiber are changed following the change in the small hole diameters in the tapered sections 14 and therefore, emitting light beams having converged emitting angles, are obtained stably at the emitting tip 10b. PCOPYRIGHT: (C)2006,JPO&NCIPI