Evidence of dissipative solitons in Yb³⁺:CaYAlO₄

Structure and spectral properties of Dy3+ doped CaYAlO4 single crystal

A 2 at.% Dy³⁺: CaYAlO₄ single crystal was grown successfully. The electronic structures of Ca²⁺/Y³⁺ mixed sites in CaYAlO₄ were investigated using first-principles based on density functional theory. The effects of Dy³⁺ doping on the structural parameters of host crystal were studied using XRD pattern. The optical properties including absorption spectrum, excitation spectrum, emission spectra and fluorescence decay curves were thoroughly investigated. The results show that the Dy³⁺: CaYAlO₄ crystal could be pumped by the blue InGaN and AlGaAs or 1281 nm laser diodes. Furthermore, an intense 578 nm yellow emission was obtained directly under excitation at 453 nm, meanwhile, evident mid-infrared light emitting was observed by 808 or 1281 nm laser excitation. The fitted fluorescence lifetimes of ⁴F_9/2 and ⁶H_13/2 levels were about 0.316 ms and 0.038 ms, respectively. It can be concluded that this Dy³⁺: CaYAlO₄ crystal could simultaneously act as a promising medium for both solid-state yellow and mid-infrared laser outputs.

Diode-pumped high-power sub-100 fs Kerr-lens mode-locked Yb:CaYAlO4 laser with 1.85 MW peak power

We demonstrated a diode-pumped high-power Kerr-lens mode-locked Yb:CaYAlO₄ (Yb:CALYO) laser with a dual-confocal cavity, directly generating 59-fs pulses with 6.2 W average power, which is the highest average power from any sub-60 fs Yb-doped solid-state lasers. With the repetition rate of 50 MHz, the corresponding single pulse energy was 124 nJ and the peak power was 1.85 MW, which to the best of our knowledge is the highest peak power delivered directly from a sub-100 fs Yb-based bulk lasers ever.

Dissipative soliton operation of a diode pumped Yb:NaY(WO₄)₂ laser

We report on the dissipative soliton operation of a diode pumped Yb:NaY(WO₄)₂ (Yb:NYW) solid-state laser. The dissipative solitons and their features as the net cavity group velocity dispersion is changed from the normal to the anomalous dispersion regime are experimentally investigated. Taking advantage of the dissipative soliton shaping of the mode-locked pulses we have generated stable near transform-limited pulses as short as 54 fs. To our knowledge, this is so far the shortest pulse directly obtained from the mode-locked Yb:NYW oscillator.

Dissipative soliton and synchronously dual-wavelength mode-locking Yb:YSO lasers

We experimentally demonstrate the dissipative soliton mode-locking operation of a Yb:YSO laser by using an all-normal dispersion cavity. Strongly chirped pulses are obtained with pulse duration of 9.3 ps at a repetition rate of 113.4 MHz. The central wavelength is 1082 nm with 3.1 nm FWHM bandwidth. A dual-wavelength synchronously mode-locking operation at central wavelengths of 1059.2 nm and 1082.2 nm is also reported. Stable mode-locked pulses are achieved with pulse duration of 10 ps and total average output power of 164 mW. Periodic ultrashort beat pulses with pulse duration of 169 fs at an ultrahigh repetition rate of 1.4 THz can be distinctly observed from the measured autocorrelation trace. To our knowledge, this is the first demonstration of dual-wavelength synchronously mode-locking operation from a Yb:YSO laser.