Diode-pumped 10 W femtosecond Yb:CALGO laser with high beam quality

Abstract We demonstrate a diode-pumped femtosecond Yb:CaGdAlO4 (Yb:CALGO) laser with a semiconductor saturable absorber mirror (SESAM) for stable mode-locking operation. A perfect beam profile is measured under 10 W output power with $M_{x}^{2}$ = 1.017 and $M_{y}^{2}$ = 1.016 in the horizontal and vertical directions, respectively. At the repetition rate of 71.66 MHz, the optical pulse duration is 247 fs and the pulse energy is 140 nJ at the central wavelength of 1041 nm, corresponding to a peak power of 0.56 MW. In addition, we also generate continuous wave (CW) power of more than 15 W with TEM00 mode, corresponding to an optical-to-optical efficiency of 44.1%.

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Stable continuous-wave mode-locked laser from a 1645 nm Er:YAG ceramic oscillator

Applied Physics Express ◽

10.35848/1882-0786/ac481c ◽

2022 ◽

Author(s):

Yangyu Liu ◽

Xue Cao ◽

AnHua Xian ◽

Guangmiao Liu ◽

Wei zhou ◽

...

Keyword(s):

Solid State ◽

Pulse Width ◽

Peak Power ◽

Continuous Wave ◽

Modulation Depth ◽

Average Power ◽

Mode Locking ◽

Wave Mode ◽

Semiconductor Saturable Absorber ◽

Continuous Wave Mode

Abstract We demonstrate stable continuous-wave mode-locking (CWML) pulses around 1645nm by employing the home-made Er:YAG ceramic. By using a fiber laser and semiconductor saturable absorber mirror (SESAM) with modulation depth of 1.2%, we get ML pulses with the output average power up to 815 mW, the pulse width shortened as ~4 ps, and the peak power of 1.8 kW. With the SESAM of modulation depth of 2.4%, the second-order harmonic ML pulses were also obtained. As far as we know, this is the first report of CWML from Er3+-doped ceramics and also the shortest pulse duration in Er3+-doped solid-state oscillators.

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Optimized Growth and Laser Application of Yb:LuAG Single-Crystal Fibers by Micro-Pulling-Down Technique

Crystals ◽

10.3390/cryst11020078 ◽

2021 ◽

Vol 11 (2) ◽

pp. 78

Author(s):

Anye Wang ◽

Jian Zhang ◽

Shuai Ye ◽

Xiaofei Ma ◽

Baiyi Wu ◽

...

Keyword(s):

Single Crystal ◽

High Power ◽

Slope Efficiency ◽

Continuous Wave ◽

Beam Quality ◽

Axial Direction ◽

Optical Quality ◽

Central Wavelength ◽

High Power Lasers ◽

Crystal Fibers

Single-crystal fibers (SCFs) have a great application potential in high-power lasers due to their excellent performance. In this work, high-quality and crack-free Yb3+:Lu3Al5O12 (Yb:LuAG) SCFs were successfully fabricated by the micro-pulling-down (μ-PD) technology. Based on the laser micrometer and the X-ray Laue diffraction results, these Yb:LuAG SCFs have a less than 5% diameter fluctuation and good crystallinity along the axial direction. More importantly, the distribution of Yb ions is proved to be uniform by electron probe microanalysis (EPMA) and the scanning electron microscope (SEM). In the laser experiment, the continuous-wave (CW) output power using a 1 mm diameter Yb:LuAG single-crystal fiber is determined to be 1.96 W, at the central wavelength of 1047 nm, corresponding to a slope efficiency of 13.55%. Meanwhile, by applying a 3 mm diameter Yb:LuAG SCF, we obtain a 4.7 W CW laser output at 1049 nm with the slope efficiency of 22.17%. The beam quality factor M2 is less than 1.1 in both conditions, indicating a good optical quality of the grown fiber. Our results show that the Yb:LuAG SCF is a potential solid-state laser gain medium for 1 μm high-power lasers.

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