Near infrared diode-pumped lasing of femtosecond-laser-written Pr:LiLuF4 waveguide

In this Letter we report the near infrared operation of a femtosecond-laser-written diode-pumped Pr:LiLuF 4 waveguide laser. By employing a circular depressed-cladding waveguide with propagation losses as low as 0.19 dB/cm, we demonstrated lasing at 914 nm, with a maximum output power of 140 mW and a slope efficiency of 24%. Moreover, we demonstrated the possibility of lasing in a waveguide device at 894 nm, 922 nm and 933 nm. To the authors knowledge, this is the first demonstration of a Pr-based waveguide laser operating in this spectral region. • Praseodymium ions show emission in the 900 nm band, allowing near infrared lasing. • Lasers in the 900 nm band have applications in the medical field. • Femtosecond laser written waveguides lead to compact and high efficiency lasers. • Compact devices can play a key role in integrated optical systems.