[21p-E203-1~5] 3.5 Laser system and materials

△ [21p-E203-4] A novel phase control method for coherent polarization beam combination

〇Rei Sakakibara¹, Norikatsu Mio^1,2 (1.Univ. of Tokyo. Dep of Appl. Phys., 2.Univ. of Tokyo. IPST)

Keywords:coherent beam combination

In various laser applications, high power and high quality laser beams are required. Although, fiber lasers and fiber amplifiers are promising devices for obtaining such laser beams, they have a certain upper limit concerning their output power because nonlinear effects of optical fibers become significant and degrade the beam quality. Coherent beam combination is the method of combining several beams to overcome the power limitations. Here, we have used a polarizing beam splitter to combine two beams. This method is called coherent polarization beam combination. In order to obtain a stable output polarization state, we have to control a relative phase between two input beams; in this method the output polarization state depends on the relative phase. Although in an ordinary system, the input beams are phase-modulated to control the relative phase, we have developed a method without any modulation of the beams. Furthermore, we have demonstrated and verified this novel method.