Chengcheng Li,Zeliang Gao,Zhongjun Zhai,Shuai Ye,Youxuan Sun
A Cr4+-doped TiTe3O8crystal with dimensions up to 21 mm × 21 mm × 11 mm was grown successfully by the top-seeded solution growth method. A high-resolution X-ray diffraction experiment showed that the full width at half-maximum of the rocking curve was 41.90″. Energy-dispersive spectrometry (EDS) and X-ray fluorescence spectroscopy (XRF) proved that Cr4+ions have been doped into the TiTe3O8crystal with molar percentage of 4.9%. The Cr:TiTe3O8crystal exhibited an absorption range from 995 to 1565 nm, which is suitable for passive Q switch at 1064 nm. Then, a passive Q-switching solid-state laser operating at 1064 nm was realized using a Cr:TiTe3O8crystal as the saturable absorber. The maximum laser pulse energy is calculated to be 0.7 μJ, and the maximum peak power reaches 0.7 W.Keywords:Cr:TiTe3O8;passive Q-switching;top seed solution method
Jin-hui Chen,Guo-qing Deng,Shao-cheng Yan,Cheng Li,Kai Xi,Fei Xu,Yan-qing Lu
Based on the liquid exfoliated method, we obtained the few-layer molybdenum disulfide (MoS2) nanoplates solution. By thermal evaporation method, we directly deposited MoS2 thin film onto the facet of a fiber patch cord. The modulation depth of the film is as high as 29%, and a Q-switched fiber laser was achieved. We also provided a new method to continuously tune the output laser with a tuning sensitivity of ∼5.5 nm/(1% strain) by controlling the cavity loss with a strained microfiber coupler (MFC).
We reported on a passively Q-switched double-clad thulium-doped fiber laser by using oxygen vacancies (OVs) enriched with MoO3-x as a saturable absorber (SA). The MoO3-x was successfully embedded in polyvinyl alcohol and acted as the SA for a stable Q-switching operation in the 2 µm wavelength region. Stable Q-switched pulses were obtained at a central wavelength of ∼1992.1 nm with a maximum output power of ∼62.7 mW, maximum pulse energy of ∼1.63 µJ and a minimum pulse duration of ∼2 µs. The repetition rate of the pulses can be tuned from ∼15.5 kHz to ∼38.5 kHz with increasing the pump power. Our experiment was the first demonstrated use of MoO3-x as a SA for pulse laser generation, in which OVs were considered as the original reason for the optical saturable absorption. Moreover, it provides a novel idea for optical SA preparation by controlling the vacancy defects in such materials.
An all-fiber passively Q-switched ytterbium-doped fiber laser (YDFL) was successfully achieved by using a single-walled carbon nanotube (SWCNT) as a saturable absorber (SA). The SWCNT was fabricated by pyrolyzing tripropylamine in the one-dimensional channel of zeolite single crystal (ZnAPO-5, framework type code: AFI). Zn 2+ metal cations were doped to promote the filling density and quality of the SWCNT. Subsequently, by incorporating the SA into an YDFL ring cavity, a stable Q-switched pulse train at 1039.4 nm with a repetition rate of 54.28 kHz was obtained when the pump power elevated to the starting threshold of 245 mW. It proved that this SWCNT@AFI SA can be used as an effective passively Q-switched for operation at 1.0 µm region.