2026/01/01 by Firas Trawi, Marin Hamrouni, Zekican Erturk +3 · 1 voice
Engineering · Physics and Astronomy · #Solid State Laser Technologies #Photorefractive and Nonlinear Optics #Advanced Fiber Laser Technologies
paper · doi:10.1051/jeos/2026040
openalex publication_date 2026/01/01 · openalex created_date 2026/04/20 · openalex updated_date 2026/07/23
We report a high-power, high-efficiency continuous-wave Tm:KY(WO 4 ) 2 (Tm:KYW) laser based on multimode in-band diode pumping at 1720 nm. In-band pumping reduces the quantum defect compared to conventional 800-nm pumping, enabling efficient high-power operation. We demonstrate up to 4.55 W of output power near 1.94 μm with a slope efficiency of 83% with respect to absorbed pump power, approaching the quantum-defect limit. The laser provides smooth wavelength tunability from 1839 to 2100 nm and maintains near-diffraction-limited transverse beam quality across the full operating range. These results indicate that multimode in-band pumping of Tm:KYW is a simple and compact route to efficient, broadband, high-power sources in the 1.9–2.0 μm region, providing a practical basis for future high-power Q-switched and mode-locked systems.