Generation of sub-50fs soliton pulses from a mode-locked Yb,Na:CNGG disordered crystal laser

Kerr-lens mode-locking of an Yb:CLNGG laser

We report on a Kerr-lens mode-locked laser based on an Yb³⁺-doped disordered calcium lithium niobium gallium garnet (Yb:CLNGG) crystal. Pumping by a spatially single-mode Yb fiber laser at 976 nm, the Yb:CLNGG laser delivers soliton pulses as short as 31 fs at 1056.8 nm with an average output power of 66 mW and a pulse repetition rate of ∼77.6 MHz via soft-aperture Kerr-lens mode-locking. The maximum output power of the Kerr-lens mode-locked laser amounted to 203 mW for slightly longer pulses of 37 fs at an absorbed pump power of 0.74 W, which corresponds to a peak power of 62.2 kW and an optical efficiency of 20.3%.

RE3+-Doped Ca3(Nb,Ga)5O12 and Ca3(Li,Nb,Ga)5O12 Crystals (RE = Sm, Dy, and Pr): A Review of Current Achievements

Spectroscopic characteristics of RE³⁺ ions (RE = Sm, Dy, and Pr) doped in partially disordered Ca₃Nb_1.6875Ga_3.1875O₁₂-CNGG and Ca₃Li_0.275Nb_1.775Ga_2.95O₁₂-CLNGG crystals are reviewed in detail to assess their prospects as laser crystals with emission in the visible spectral domain. All investigated crystals were grown using the Czochralski crystal growth technique. High-resolution absorption and emission measurements at different temperatures, as well as emission dynamics measurements, were performed on the grown crystals. The spectroscopic and laser emission characteristics of the obtained crystals were determined based on the Judd-Ofelt parameters. The obtained results indicate that CNGG:RE³⁺ and CLNGG:RE³⁺ (RE = Sm, Dy, and Pr) crystals can be promising materials for lasers in the visible range.

SWCNT-SA mode-locked Tm,Ho:LCLNGG laser

Sub-100 fs pulse generation from a passively mode-locked Tm,Ho-codoped cubic multicomponent disordered garnet laser at ∼2 µm is demonstrated. A single-walled carbon nanotube saturable absorber is implemented to initiate and stabilize the soliton mode-locking. The Tm,Ho:LCLNGG (lanthanum calcium lithium niobium gallium garnet) laser generated pulses as short as 63 fs at a central wavelength of 2072.7 nm with an average output power of 63 mW at a pulse repetition rate of ∼102.5 MHz. Higher average output power of 121 mW was obtained at the expense of longer pulse duration (96 fs) at 2067.6 nm using higher output coupling. To the best of our knowledge, this is the first report on mode-locked operation of the Tm,Ho:LCLNGG crystal.

Sub-100 fs mode-locked Tm:CLTGG laser

We report on the first sub-100 fs mode-locked laser operation of a Tm³⁺-doped disordered calcium lithium tantalum gallium garnet (Tm:CLTGG) crystal. Soliton mode-locking was initiated and stabilized by a transmission-type single-walled carbon nanotube saturable absorber. Pulses as short as 69 fs were achieved at a central wavelength of 2010.4 nm with an average power of 28 mW at a pulse repetition rate of ∼87.7 MHz. In the sub-100 fs regime, the maximum average output power amounted to 103 mW.

Yb:GdScO3 crystal for efficient ultrashort pulse lasers

We present, to the best of our knowledge, the first demonstration of thermal, optical, and laser properties of Yb:GdScO₃ for potentially efficient ultrashort pulse lasers. The stimulated emission cross section at 1025 nm (E//c) is 0.46×10^-20cm² with the emission band width of 85 nm, even broader than the well-known Yb:CaGdAlO₄. It has quite a high thermal conductivity of 5.54W/(m⋅K) at 50°C, comparable with Yb:YAG. In the continuous-wave regime, the maximum output power of 13.45 W at 1063.9 nm was generated with the optical-to-optical efficiency of 63.3%. These results suggest that the Yb:GdScO₃ crystal is a promising candidate for ultrashort pulse lasers.

Sub-five-optical-cycle pulse generation from a Kerr-lens mode-locked Yb:CaYAlO4 laser

Direct generation of ultrashort few-optical-cycle pulses in various wavelength regions has attracted great attention in recent decades. In this paper, generation of less than five-optical-cycle pulses from a Kerr-lens mode-locked ${\rm Yb}{:}{\rm CaYAlO}_4$ laser is demonstrated. Pumped by a 976 nm fiber laser, stable near-Fourier-transform-limited ultrashort soliton pulses centered around 1080 nm with a repetition rate of ${\sim}{113.7}\;{\rm MHz}$ were obtained. The obtained pulses have a pulse duration as short as 17 fs if a ${{\rm Sech}^2}$-shaped pulse profile is assumed, corresponding to about 4.68 optical cycles. To the best of our knowledge, this is the shortest pulse directly generated from mode-locked rare-earth-doped solid-state oscillators.

78 fs SWCNT-SA mode-locked Tm:CLNGG disordered garnet crystal laser at 2017 nm

A passively mode-locked Tm:CLNGG laser using single-walled carbon nanotubes (SWCNT) as a saturable absorber (SA) is demonstrated at 2017 nm. Pulses as short as 78 fs are generated at an 86 MHz repetition rate with an average output power of 54 mW. By increasing the output coupling from 0.5% to 1.5%, a higher power of 100 mW is achieved for slightly longer pulses with a duration of 105 fs at 1996 nm.

Crystal growth and properties of the disordered crystal Yb:SrLaAlO4: a promising candidate for high-power ultrashort pulse lasers

A high quality Yb³⁺-doped strontium lanthanum aluminate crystal, Yb:SrLaAlO₄ is grown by the Czochralski method.