Study on 1.9 μm structured lasers based on Ince–Gaussian modes superposition with multi-modulation by different directions off-axis dual-end-pump

The double IGp,pe modes multi-modulation superposition evolution structured lasers output is realized, based on the proposed different directions off-axis dual-end-pumping Tm:YLF laser method. Under the modes orthogonal superposition, the theoretical simulation and experimental measurement results have a high degree of agreement, and the orthogonal superposition of double IGp,pe modes within 5 orders is realized, which proves that different order modes and optical field intensity ratio have the capability to modulate the formation of vortex array structured beams. When the low-order IGp,pe modes of the same order are orthogonally superimposed, the phenomenon of superposition of different phase differences occurs, which proves the possibility of modulating the superposition of IGp,pe modes by the phase difference. At the same time, it is found that the regular pattern output of high-order IGp,m modes (odd mode m ≤ 3 or even mode m ≤ 2) can be realized at different angles, which proves the ability of rotation angle to modulate the superposition of double IGp,pe modes. Finally, the 1.9μm Tm:YLF structure laser output with double IGp,pe modes multi-factor composite modulation superposition evolution within 10 orders is realized. When the 10-order double IG10,10e modes are superimposed, the output power exceeds 5.7 W, and the conversion efficiency is higher than 17.5%.