Generation of 1.8 W Continuous Green Laser at 532 nm by Passively Resonant Enhancement Technique in a Fiber Laser

In this paper, design and fabrication of an internal resonant enhanced frequency doubling of the continuous-wave ytterbium-doped fiber laser at 1064nm using a Fabry-Perot bow tie cavity inside the fiber laser cavity is presented. The 3.5W power coupled into the enhancement cavity is amplified to 163W by the intracavity passive locking technique. By placing an LBO crystal within this resonant enhancement cavity, conversion efficiency of the second harmonic generation of the laser in continuous regime is increased from 0.023% to 51.42% (i.e. about 2200 times) which results to generation of 1.8W light at 532nm.