高NA石英ファイバによる高密度レーザー伝送

抄録

A high NA silica fiber has been developed by Mitsubishi Cable Industries Ltd. for the exclusive application to ultrathin fiber scopes and small diameter catheter which are used for various micro diagnosis and therapy in the body. This report describes the detailed study of high density laser power transmission on this high NA silica fiber. Following fibers were utilised for this study
·Ge doped silica glass core-B·F. dope silica glass clad fiber (HiNA/All silica) -0.43NA
·Ge doped silica glass core-polymer clad fiber (HiNA/PCF) -0.53NA
·Pure silica core-B·F dope silica glass fiber (Pure silica core/All silica) -0.20NA
·Pure silica core-polymer clad fiber (Pure silica core/PCF) -0.40NA
·Tapered fiber of both types.
·Core diameter covers 50-500μm
And the laser utilised are,
·50W CW Nd-YAG (λ=1.06μm)
·15W pulse KTP Nd -YAG (λ=1.06, 0.53μm)
·25W Diode laser (λ=0.806μm)
As results
·70% power transmission, 34W out put power and 17.3 KW out put power were achieved for CW Nd-YAG laser and HiNA/All silica fiber having 56μm core diameter.
·Break down thresh old power of HiNA fiber to puls Nd-YAG laser was 1/2~1/10 of that of pure silica fiber.
·On diode laser transmission with a taperd fiber having 400μm core diameter of laser input portion 160μm core diameter of out put portion and 0.53NA, 70% power transmission and 17.5W out put power were achieved.