Study on π-polarized 1084 nm CW laser based on Nd3+ doped MgO:LiNbO3 with the end-face double-focus coupling pumping mode.

• A 4.3 W π -polarized 1084 nm single-wavelength CW laser with a single circular spot output is obtained. • The oscillation of σ -polarized 1093 nm laser is suppressed successfully. • The thermal model of Nd:MgO:LN under different pumping modes is established. • The single circular spot laser is realized based on the double-focus coupling pumping mode by optimizing the design of the resonator. A π -polarized 1084 nm continuous wave(CW) laser based on a-cut Nd3+ doped MgO:LiNbO 3 (Nd:MgO:LN) with the end-face double-focus coupling pumping mode is reported. The reason for the dual-wavelength laser is explained from the perspective of Nd:MgO:LN energy level, the thermal model of Nd:MgO:LN is established, the temperature field distribution in the crystal under different pumping modes is analyzed, and the laser spot morphology of the output mirror at different positions is simulated. In the experiment, compared with the traditional end-face single-focus pumping mode, it is experimentally verified that the thermal management of Nd:MgO:LN can be effectively realized with the end-face double-focus coupling pumping mode, σ -polarized 1093 nm laser is suppressed successfully, the phenomenon of orthogonally polarized dual-wavelength alternating output or simultaneous output does not appear, the advantage is obvious under high-power pumping. And the single circular spot laser is realized based on the double-focus coupling pumping mode by optimizing the design of the resonator. Finally, a 4.3 W π -polarized 1084 nm single-wavelength CW laser with a single circular spot output is obtained. [ABSTRACT FROM AUTHOR]