Stable CW Single-Mode Photonic Crystal Fiber DFB Ring Laser

We demonstrate stable single-mode CW operation of a DFB ring laser based on Er P P doped photonics crystal fiber (PCF). The incorporation of a ring cavity allows one single mode to lase and also suppresses the unwanted effect of self-pulsing. Such a narrow linewidth source in PCF has great potential in spectroscopy. TP F FPT