Filters

2019 - 201912020 - 20212

More filters

20223
Reset filters

Settings

Author: Pan, Zhongben ×

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Graphene mode-locked Tm,Ho-codoped crystalline garnet laser producing 70-fs pulses near 21 µm
    (Washington, DC : OSA, 2019) Zhao, Yongguang; Chen, Weidong; Wang, Li; Wang, Yicheng; Pan, Zhongben; Dai, Xiaojun; Yuan, Hualei; Cai, Huaqiang; Zhang, Yan; Bae, Ji Eun; Park, Tae Gwan; Rotermund, Fabian; Loiko, Pavel; Serres, Josep Maria; Mateos, Xavier; Shen, Deyuan; Griebner, Uwe; Petrov, Valentin
    Bilayer graphene synthesized by chemical vapor deposition is successfully applied as a saturable absorber (SA) for the passive mode-locking of a Tm,Ho:CLNGG laser at 2093nm. Near transform-limited pulses as short as 70 fs, i.e., 10 optical cycles, are produced at a 89 MHz repetition rate with 69 mW average output power. To the best of our knowledge, these are the shortest pulses ever reported from graphene-SA mode-locked Tm, or Ho-lasers in the 2 µm spectral region, including bulk and fiber lasers.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    Tm3+-doped calcium lithium tantalum gallium garnet (Tm:CLTGG): novel laser crystal
    (Washington, DC : OSA, 2021) Alles, Adrian; Pan, Zhongben; Loiko, Pavel; Serres, Josep Maria; Slimi, Sami; Yingming, Shawuti; Tang, Kaiyang; Wang, Yicheng; Zhao, Yongguang; Dunina, Elena; Kornienko, Alexey; Camy, Patrice; Chen, Weidong; Wang, Li; Griebner, Uwe; Petrov, Valentin; Solé, Rosa Maria; Aguiló, Magdalena; Díaz, Francesc; Mateos, Xavier
    We report on the development of a novel laser crystal with broadband emission properties at ∼2 µm – a Tm3+,Li+-codoped calcium tantalum gallium garnet (Tm:CLTGG). The crystal is grown by the Czochralski method. Its structure (cubic, sp. gr. 𝐼𝑎3¯𝑑, a = 12.5158(0) Å) is refined by the Rietveld method. Tm:CLTGG exhibits a relatively high thermal conductivity of 4.33 Wm-1K-1. Raman spectroscopy confirms a weak concentration of vacancies due to the charge compensation provided by Li+ codoping. The transition probabilities of Tm3+ ions are determined using the modified Judd-Ofelt theory yielding the intensity parameters Ω2 = 5.185, Ω4 = 0.650, Ω6 = 1.068 [10−20 cm2] and α = 0.171 [10−4 cm]. The crystal-field splitting of the Tm3+ multiplets is revealed at 10 K. The first diode-pumped Tm:CLTGG laser generates 1.08 W at ∼2 µm with a slope efficiency of 23.8%. The Tm3+ ions in CLTGG exhibit significant inhomogeneous spectral broadening due to the structure disorder (a random distribution of Ta5+ and Ga3+ cations over octahedral and tetrahedral lattice sites) leading to smooth and broad gain profiles (bandwidth: 130 nm) extending well above 2 µm and rendering Tm:CLTGG suitable for femtosecond pulse generation.