Line-tunable Er:GGAG laser

Abstract

In this Letter, for the first time, to the best of our knowledge, a pulse and CW laser based on an Er-doped GdGaAlO (Er:GGAG) active medium emitting laser radiation at 2.8 μm are presented. With the longitudinal diode pumping, the maximal output energy of 4.9 mJ and slope efficiency of 13.5% in the pulse regime were reached. Using the birefringent MgF plate, the line tunability of Er:GGAG at several spectral bands of 2800-2822 nm, 2829-2891 nm, and 2917-2942 nm were obtained.

Diode-pumped laser and spectroscopic properties of Yb,Ho:GGAG at 2 µm and 3 µm

“…Because of the high variation of lifetime in Ho 3+ energy levels two different pump pulse durations of 5 ms ( 5 I 7 ) and 2 ms ( 5 I 6 ) were used during laser experiments. It has to be noted that because of the ratio between the fluorescence decay times at the upper 5 I 6 (309 µs) and lower 5 I 7 (7.8 ms) energy levels, the Yb,Ho:GGAG can suffer from a self-termination (bottleneck) effect at the ∼3 µm transition, similarly to erbium-doped active media [4,11]. It is also interesting to compare the measured decay time of Yb 3+ ( 2 F 5/2 level) in the GGAG crystal with (190 µs) and without Ho 3+ (917 µs) codoping [14], which proves the efficiency of the Yb 3+ → Ho 3+ energy transfer.…”

“…The well-known YAG crystal doped by Yb and Ho was also tested; however, only 2.1 µm laser emission was presented [8]. As shown in [4] we believe the main benefit of GGAG crystal is the relatively broad tuning range and shifting the emission wavelength closer to 3 µm, which can be advantageous for potential applications.…”

“…The ∼3 µm lasers can also be used as a pumping source for Fe 2+ -doped ZnSe or ZnS which possess a strong absorption cross-section near 3 µm [2,3]. Using direct diode pumping of the upper laser level 4 I 11/2 in erbium-doped materials (YAG, YSGG, YLF, GGAG, etc) it is possible to obtain lasing between the 4 I 11/2 → 4 I 13/2 energy levels, which corresponds with laser radiation from 2.7 µm to 2.94 µm [4]. Aside from erbium ions, only dysprosium (Dy 3+ , 6 H 11/2 → 6 H 15/2 ) and holmium (Ho 3+ , 5 I 6 → 5 I 7 ) allow the generation of laser radiation close to 3 µm [5,6] if diode pumping is used.…”

“…For illustration, in figure 1 the simplified energy levels of Yb,Ho-doped active media are presented. Similarly to erbium, the Ho-doped active media suffer from the self-termination (bottleneck) effect since the fluorescence decay time at the upper laser level 5 I 6 is shorter Laser Physics Letters Diode-pumped laser and spectroscopic properties of Yb,Ho:GGAG at 2 µm and 3 µm in comparison with the lower laser level 5 I 7 [4]. Even though there is a self-termination effect at ∼3 µm the lasing from diode-pumped Yb,Ho-doped bulk crystal (YSGG) was successfully presented in [6].…”

Development and prospects of garnet ceramic scintillators: A review

“…However, it also provides a new way of thinking to delve into the specificity of the multicomponent garnets. It is worth mentioning that in addition to the application in the scintillators, it is also easier for the multicomponent garnet to achieve ultrashort pulse lasers with wavelength tunability due to the wider emission band [220][221][222][223]. Moreover, due to the higher brightness and tunable luminescence, the multicomponent garnets can also be prepared into phosphors and ceramics for high-power white LEDs by introducing different luminescent centers [224,225].…”