High power single-mode fiber laser and a multi-mode delivery cable

Over 500W output power Yb doped single-mode fiber laser demonstrates excellent beam quality of less than 1.1 M2 value. Use of single mode fiber as delivery cable enables small spot-size; however delivery length is limited by SRS in fiber. To mitigate this characteristic, use of multi-mode fiber for delivery is one of approach. We present our design of 500W single mode fiber laser and beam quality measurement of multi-mode delivery fiber. How they vary, how we can homogenize beam depend on different condition of connection style, etc. We also present material process results in different beam performance.