실험계획법(DOE)를 활용한 빔 확산형 광섬유 제작조건 최적화 연구

Abstract

The optical connector, which is essential for optical communications, undergoes changes in loss due to repeated coupling/decoupling since it relies on physical contact, and there is a possibility of increased loss due to contamination of the contact surface. To address these issues, an “expanded-beam fiber optic” that collects or makes parallel light from optical fibers is proposed, using ball lenses and spherical/aspherical lenses to connect with optical fibers. This method has relatively long working distances and high efficiency but has several problems, including difficulty in aligning with optical fibers and small-scale production. To address these issues, this study proposes a fabrication method for an “expanded-beam fiber optic” using graded index multi-mode fiber(GRIN-MMF) that can be directly spliced with fiber optics instead of lenses. This fiber is fabricated by directly splicing GRIN-MMF with single mode fibers, which core diameters is 85 and 100 micrometers. To optimize the splicing conditions between single mode and multi-mode fiber, the value of parameters such as arc current, taper, and overlap were determined using a design of experiment (DOE) method. In addition, silica was inserted between single-mode and multimode fiber to reduce the mode dispersion effect caused by the center dip of the multimode fiber. As a result, the final “expanded-beam fiber optic” fabricated by this method was confirmed to enable communication with losses of less than 0.7-0.8 dB at working distances of 300-350 micrometers. By utilizing the “expanded-beam fiber optic” produced through this study, it is expected to construct optical communication systems that can be applied to rotating structures such as RADAR and wind power generation.