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Now showing 1 - 4 of 4
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    Multi-millijoule, few-cycle 5 µm OPCPA at 1 kHz repetition rate
    (Washington, DC : Soc., 2020) von Grafenstein, Lorenz; Bock, Martin; Ueberschaer, Dennis; Escoto, Esmerando; Koç, Azize; Zawilski, Kevin; Schunemann, Peter; Griebner, Uwe; Elsaesser, Thomas
    A table-top midwave-infrared optical parametric chirped pulse amplification (OPCPA) system generates few-cycle pulses with multi-10 GW peak power at a 1 kHz repetition rate. The all-optically synchronized system utilizes ZnGeP2 nonlinear crystals and a highly stable 2 µm picosecond pump laser based on Ho:YLiF4. An excellent energy extraction is achieved by reusing the pump pulse after the third parametric power amplification stage, resulting in 3.4 mJ idler pulses at a center wavelength of 4.9 µm. Pulses as short as 89.4 fs are achieved, close to only five optical cycles. Taking into account the pulse energy, a record high peak power of 33 GW for high-energy mid-IR OPCPAs beyond 4 µm wavelength is demonstrated. © 2020 OSA - The Optical Society. All rights reserved.
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    Sub-100 fs mode-locked Tm:CLTGG laser
    (Washington, DC : Soc., 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.
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    SESAM mode-locked Tm:Y2O3 ceramic laser
    (Washington, DC : Soc., 2022) Zhang, Ning; Liu, Shande; Wang, Zhanxin; Liu, Jian; Xu, Xiaodong; Xu, Jun; Wang, Jun; Liu, Peng; Ma, Jie; Shen, Deyuan; Tang, Dingyuan; Lin, Hui; Zhang, Jian; Chen, Weidong; Zhao, Yongguang; Griebner, Uwe; Petrov, Valentin
    We demonstrate a widely tunable and passively mode-locked Tm:Y2O3 ceramic laser in-band pumped by a 1627-nm Raman fiber laser. A tuning range of 318 nm, from 1833 to 2151 nm, is obtained in the continuous-wave regime. The SESAM mode-locked laser produces Fourier-transform-limited pulses as short as 75 fs at ∼ 2.06 µm with an average output power of 0.26 W at 86.3 MHz. For longer pulse durations of 178 fs, an average power of 0.59 W is achieved with a laser efficiency of 29%. This is, to the best of our knowledge, the first mode-locked Tm:Y2O3 laser in the femtosecond regime. The spectroscopic properties and laser performance confirm that Tm:Y2O3 transparent ceramics are a promising gain material for ultrafast lasers at 2 µm.
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    Watt-level femtosecond Tm-doped “mixed” sesquioxide ceramic laser in-band pumped by a Raman fiber laser at 1627 nm
    (Washington, DC : Soc., 2022) Zhang, Ning; Wang, Zhanxin; Liu, Shande; Jing, Wei; Huang, Hui; Huang, Zixuan; Tian, Kangzhen; Yang, Zhiyong; Zhao, Yongguang; Griebner, Uwe; Petrov, Valentin; Chen, Weidong
    We report on a semiconductor saturable absorber mirror mode-locked Tm:(Lu,Sc)2O3 ceramic laser in-band pumped by a Raman fiber laser at 1627 nm. The nonlinear refractive index (n2) of the Tm:(Lu,Sc)2O3 ceramic has been measured to be 4.66 × 10-20 m2/W at 2000 nm. An average output power up to 1.02 W at 2060 nm is achieved for transform-limited 280-fs pulses at a repetition rate of 86.5 MHz, giving an optical efficiency with respect to the absorbed pump power of 36.4%. Pulses as short as 66 fs at 2076 nm are produced at the expense of output power (0.3 W), corresponding to a spectral bandwidth of 69 nm. The present work reveals the potential of Tm3+-doped sesquioxide transparent ceramics for power scaling of femtosecond mode-locked bulk lasers emitting in the 2-μm spectral range.