RESUMO
Depressed-cladding surface channel waveguides were inscribed in a 0.5 at.% Pr:LiYF4 crystal by femtosecond Direct Laser Writing. The waveguides consisted of a half-ring cladding (inner diameter: 17â µm) and side structures ("ears") improving the mode confinement. The waveguide propagation loss was as low as 0.14 ± 0.05â dB/cm. The orange waveguide laser operating in the fundamental mode delivered 274â mW at 604.3â nm with 28.4% slope efficiency, a laser threshold of only 29â mW and linear polarization (π), representing record-high performance for orange Pr waveguide lasers.
RESUMO
We report on the first laser operation of a Sm3+-doped monoclinic KGd(WO4)2 double tungstate crystal in the red spectral range. Pumped by a frequency-doubled optically pumped semiconductor laser (2ω-OPSL) at 479.1â nm, the 0.8 at. % Sm:KGd(WO4)2 laser generated an output power up to 17.6â mW at 649.1â nm (the 4G5/2 â 6H9/2 transition) with a slope efficiency of 16.9%, a laser threshold down to 29â mW and a linear polarization. The laser exhibited a self-pulsing behavior, delivering µs-long pulses with a repetition rate of a few kHz. The polarized spectroscopic properties of Sm3+ ions were determined as well.
RESUMO
We report on the first deep-red laser operation of a heavily Eu3+-doped cesium gadolinium double molybdate crystal with a perfect cleavage. A 17 at. % Eu:CsGd(MoO4)2 laser based on cleaved single-crystal plates generated a maximum continuous-wave output power of 212â mW at 703.1â nm (5D0 â 7F4 transition) with a slope efficiency of 30.1%, a low laser threshold of 51â mW, linear polarization, and a beam quality factor M2 = 1.6-1.7. This monoclinic crystal is promising for deep-red microchip lasers.