tailieunhanh - Review of Fabrication Techniques for Fused Fiber Components for Fiber Lasers

Misalign- ment will lead to non-regular channels and thereforemay interfere with the bonding technique; in severe cases, it may lead to the destruction of the complete device. A correct alignment will lead to only small deviations fromthe desired elliptical shape, and the distortion while the bonding process takes place will be minimum. Align- ment techniques used to avoid errors can be simplemechanicalmethods (. use of alignment pins), edge catches in a specially designed assembling device or optical methods such as laser alignment. These methods are easily automated as shown in the semiconductor technology. In fact, most of the methods come from silicon processing technology where precise alignment ofmultiplemask layers. | This paper has been published in SPIE Photonic West 09 Fiber Lasers VI Technology Systems and Applications Proc. 7195 and is made available as an electronic preprint with permission of SPIE. Copyright 2009 Society of Photo-Optical Instrumentation Engineers. Review of Fabrication Techniques for Fused Fiber Components for Fiber Lasers Invited Paper Baishi Wang Eric Mies Vytran LLC 1400 Campus Drive Morganville NJ 07751 ABSTRACT Fused fiber components are the key building blocks that enable reliable and efficient operation of high power fiber lasers. In this paper we review fabrication techniques for the manufacture of such devices including mode-field adaptors fiber tapers fused couplers and fused combiners. We present the basic equations governing both the optical performance and fabrication requirements for these devices and demonstrate how these apply to some common fiber laser applications. We then describe and discuss component fabrication techniques and available hardware. Keywords Fusion process specialty fiber fused fiber components diffusion taper mode adapting combiner fiber laser beam propagation 1. INTRODUCTION Fiber lasers have been increasingly used for various industrial applications such as material processing marking cutting and welding because of their high optical-to-optical and overall wall-plug efficiency and excellent output beam quality 1 2 . CW fiber lasers with multi-kW power levels from a single fiber have been demonstrated 1 3 and compact low cost pulsed fiber lasers with high peak power have been developed 4 . With the availability of fiber Bragg gratings and fiber coupled pump diodes a fully monolithic . all fiber system architecture can be achieved with appropriate fused components. A fully fused system fully exploits the inherent advantages of fiber laser systems including simplicity compactness robustness and reliability. For a typical all-fiber fiber laser system there are a number of fused components that must be considered .