Development on advanced functional optical fibers
Optical fiber is a key technology for recent trends on optical researches,and its products and services penetrate in our life style deeply, such as optical network and high power fiber lasers.Especially, high power fiber lasers have been well developed because the output beam pattern of optical fiber is very good due to the waveguide geometry and the efficiency of fiber laser is higher than the ordinary solid-state laser structures.As the power of infrared laser diodes (LD) is growing more and more, high power fiber laser is actively developed, then kW-class CW single mode fiber lasers have released by some manufacturers”1”.Such lasers are now widely used in welding and cutting process in industry.Thus optical fiber and fiber laser researches well spread in the world (Fig.1) and we have also installed an optical fiber drawing system and are trying to produce new functional fiber devices fusing silica based materials and useful functional doping elements or structures.In this talk, I give an overview of high power optical fiber laser researches, and also introduce our recent optical fiber research activities in ILE.We have some unique technologies to make interesting optical fibers.1) Pr and Dy doped waterproof fluoride glass fiber for new visible fiber lasers”2”Pr and Dy doped fluoride fiber have several fluorescence in visible, such as 488, 523, 605, 635, 719 nm for Pr, 482, 575, 664 nm for Dy.These fiber materials are made of fiuoro-alminate glass, not ZBLAN.The new fluoride glass is about 500 times tougher than ZBLAN for water solubility.We have already demonstrated the fiber laser operation of 1.8 W at 638nm, and such higher power color lasers will be more useful for cutting and welding for copper or silver metal, and of course the colorful lasers are available for laser display and many medical applications.2) Bi doped silica glass and fiber Bi luminescence in near infrared region was newly discovered in 2001 by our group”3”.The luminescence is very wide between1000 and 1600 nm.I will show the properties of Bi doped silica glass and fiber.3) High rare earth concentration silica fiber made by Zeolite method”4”Zeolite method is the technology to get high concentration of rare earth ion in silica glass.Zeolite is an ion exchange material made from Si, Al, O, and alkaline ions, and it assists rare earth ions to disperse homogeneously in silica glass without rare earth oxide clustering.This technology makes around 10 times higher concentration than past doping technology and allows us to make very short length fiber laser with mm-order, and a planar-core optical fiber with a special core/clad shape.In the near future, this technology may be applied for 100 GHz optical clock or optical integrated circuits.
Yasushi Fujimoto
Institute of Laser Engineering, Osaka University, 2-6, Yamada-oka, Suita, Osaka 565-0871,JAPAN
国内会议
杭州
英文
2-4
2014-05-15（万方平台首次上网日期，不代表论文的发表时间）