2021, Wang, Li, Chen, Weidong, Pan, Zhongben, Loiko, Pavel, Bae, Ji Eun, Rotermund, Fabian, Mateos, Xavier, Griebner, Uwe, Petrov, Valentin

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.

2021, Suzuki, Anna, Kränkel, Christian, Tokurakawa, Masaki

We present a combined gain media Kerr-lens mode-locked laser based on a Tm:Lu2O3 ceramic and a Tm:Sc2O3 single crystal. Pulses as short as 41 fs, corresponding to less than 6 optical cycles, were obtained with an average output power of 42 mW at a wavelength of 2.1 μm and a repetition rate of 93.3 MHz. Furthermore, a maximum average power of 316 mW with a pulse duration of 73 fs was achieved.

2021, Zeng, Huangjun, Lin, Haifeng, Lin, Zhanglang, Zhang, Lizhen, Lin, Zhoubin, Zhang, Ge, Petrov, Valentin, Loiko, Pavel, Mateos, Xavier, Wang, Li, Chen, Weidong

We present a sub-50-fs diode-pumped Kerr-lens mode-locked laser employing a novel “mixed” monoclinic Yb:Ca4(Gd,Y)O(BO3)3 (Yb:GdYCOB) crystal as a gain medium. Nearly Fourier-limited pulses as short as 43 fs at 1036.7 nm are generated with an average power of 84 mW corresponding to a pulse repetition rate of ∼70.8 MHz. A higher average power of 300 mW was achieved at the expense of the pulse duration (113 fs) corresponding to an optical-to-optical efficiency of 35.8% representing a record-high value for any Yb-doped borate crystal. Non-phase-matched self-frequency doubling is observed in the mode-locked regime with pronounced strong spectral fringes which originate from two delayed green replicas of the fundamental femtosecond pulses in the time domain.