Rare-Earth-Doped Sesquioxides for Diode-Pumped High-Power Lasers in the 1-, 2-, and 3-μm Spectral Range

Abstract

Fabrication, characterization, and laser performance of an Yb:Lu 2 O 3 planar waveguide laser are reported. Pulsed laser deposition was employed to grow an 8 µm-thick Yb-doped lutetia waveguide on a YAG substrate. X-ray diffraction was used to determine the crystallinity, and spectroscopic characterization showed the absorption and emission cross-sections were indistinguishable from those reported for bulk material. When end-pumped by a diode-laser bar an output power of 7.4 W was achieved, limited by the available pump power, at a wavelength of 1033 nm and a slope efficiency of 38% with respect to the absorbed pump power.

Generation of 35-fs pulses from a Kerr lens mode-locked Yb:Lu_2O_3 thin-disk laser

“…The optical-tooptical efficiency amounted to 66% and the slope efficiency was 81%. These values are close to the best reported results with this gain material in the thin-disk configuration [22]. In order to avoid damage, we limited the pump intensity on the disk to ≈3.5 kW/cm 2 even though no hints for degradation of the laser efficiency were observed even at highest pump powers.…”

Passive Q-switching of ∼2.7 µm Er:Lu2O3ceramic laser with a semiconductor saturable absorber mirror

“…Spectroscopic analyses show that sesquioxides have long ∼2.7 µm fluorescence lifetimes, e.g., an order of magnitude longer than that of Er:YAG, while their stimulated cross sections at ∼2.7 µm are roughly the same order as that of garnets. 23) However, the passively Q-switched operation of sesquioxide ceramic lasers reported so far involves only an Er:Y 2 O 3 ceramic laser, generating pulses with duration of ∼4.5 µs and energy of 0.48 µJ at 12.6 kHz repetition rate. 24) In this paper, we report on a ∼2.7 µm Er:Lu 2 O 3 ceramic laser operating at RT passively Q-switched with a semiconductor saturable absorber mirror (SESAM).…”

Pulsed laser deposited diode-pumped 74 W Yb:Lu_2O_3 planar waveguide laser

“…An emission cross section for the sample was calculated using the Füchtbauer-Ladenburg equation assuming a unity quantum efficiency, a constant refractive index of 1.911 [12] and the reported low concentration lifetime of 820 µs [4]. The calculated emission cross section is shown in Fig.…”