Efficient visible laser emission of GaN laser diode pumped Pr-doped fluoride scheelite crystals

Abstract

In the present work we report on the growth, spectroscopy and laser results of diode pumped Pr-doped LiYF(4), LiLuF(4) and LiGdF(4) fluoride, scheelite-type structure crystals. We measured the polarisation dependent absorption and emission properties as well as the decay time of the (3)P(0) level. Exploiting the (3)P(2) absorption around 444 nm, we obtained efficient laser emission under GaN laser diode pumping on several transitions from the green to the near infrared wavelength range.

Spectroscopic properties of Pr3+:Gd3Ga5O12 crystal

“…Presently, the rapid development of blue GaN laser diode operating around 450 nm, which can be used to directly pump the 3 P 0,1,2 emitting levels of the Pr 3+ ions, promotes the investigation of visible lasers of Pr 3+ ion [3,10]. Actually, efficient continuous-wave green, orange, red and near-infrared lasers have been achieved in Prdoped fluoride scheelite crystals at room-temperature as pumped by GaN laser diode, and the best results were obtained with the maximum output power 208 mW and the highest slope efficiency 59% [12]. The perspectives for the visible lasers are linked to the development of a new generation of colour displays, new data storage techniques, holographic techniques and also in medical treatments, etc.…”

Diode-pumped Pr:YAP lasers

“…The reason for this are the weaker cross relaxation processes between the Pr 3+ -ions in laser host resulting in lower concentration quenching of the upper laser level. If compared with the Pr 3+ -ion doped fluoride crystals under GaN laser diode pumping [21][22][23] for Pr-fluorides. The lower value is supposed to be obtained by optimizing the pumping beam parameters.…”

Pr:YAlO3 microchip laser at 662 nm

“…Inset -the spectra in the range of 440 -465 nm displaying in more detail the absorption line where pumping was performed tals with relatively small phonon energy because of the absence of tetrahedral sites in the lattice [3]. In comparison with widely examined Pr:YLF crystal [5][6][7] as a Pr-fluoride representative, Pr:YAP active medium exhibits positive value of the temperature coefficient dn / dT enabling to design a microchip laser system.…”