Experimental research on kW single mode MOPA fiber laser

The home and abroad status of kW-class fiber laser is investigated. And the achievable method of kW all fiber laser and manner of controlling mode are analyzed. The ways of master-oscillator power amplifier which includes a master oscillator stage and a booster amplifier stage were used. The continuous laser of 1.08μm, biggest output power of 1.05kW is achieved respectively. And the optical-optical conversion efficiency is 77%. The beam quality is M_x² =1.43 and M_y² =1.42. The reason that beam quality is deteriorative is analyzed. In high power, part of laser which is transmitted in the fiber core originally, is leaked to inner cladding by fiber bending. Then, the beam quality is worsened by laser which was transmitted in inner cladding. For some special use, the stabilization of center wavelength is researched. Through measurement, there is no obvious variation in center wavelength with the output power increasing.