Publications by authors named "Maojie Cheng"

Article Synopsis
  • The study explores how thermal bonding and concave end faces impact the performance of 795 nm laser diodes (LD) when used to pump Tm:YAP crystals.
  • Concave end faces help to counteract thermal lensing effects, allowing for higher power output, reaching 42.5 W with a slope efficiency of 47.4% and optical-optical conversion efficiency of 41.6%.
  • Compared to flat bonding rods, the concave design improves the maximum output power and efficiencies, demonstrating its effectiveness in enhancing heat dissipation and laser performance.
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We demonstrated a 978 nm laser diode (LD) side-pumped YSGG/Er:YSGG/YSGG composite crystal with a size of Ф 3 mm × 65 mm and continuous-wave (CW) mode. By optimizing resonator length and output mirror transmittance, a maximum output power of 28.02 W is generated, corresponding to slope efficiency of 17.

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We demonstrate the thermal, spectroscopy and laser properties of Ho,Pr doped YAP crystal grown successfully by Cz method. The thermal expansion coefficient, thermal conductivity, absorption and emission spectra of Ho,Pr:YAP crystal are investigated in detail. Additionally, the level lifetimes suggest that Pr is a suitable deactivating ion for Ho:YAP crystal.

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In this work, we report on investigations of structure, spectroscopic properties and laser performances of, what we believe to be, a novel Er:YGGAG laser crystal. High crystalline quality is proved by an FWHW of XRC of 0.019°.

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We demonstrate a 968-nm LD side-pumped Er:YAP laser with concave end-faces and a working frequency of 50∼1000 Hz. The maximum average powers of 26.75 and 13.

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We demonstrate a novel Er:LuSGG active gain medium emitting laser wavelength at 2795 nm for the first time. The Er:LuSGG crystal is grown successfully by the Czochralski method with high crystalline and optical quality. The spectra properties, including absorption and fluorescence emission cross-section are presented in contrast with similar Er-doped garnet crystals.

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We demonstrate a laser diode (LD) end-pumped Er:YAP laser with dual-wavelength outputs of 2710 and 2728 nm. The maximum average powers of 739 and 738 mW are achieved in the continuous wave (CW) and pulse modes, which corresponds to optical-to-optical efficiencies of 10.1% and 12.

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We demonstrate a 966 nm laser diode (LD) side-pumped Er,Pr:GYSGG laser crystal operated at 2.79 μm under a high repetition rate. The lifetimes of the upper level I4 and lower level I4 are 0.

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We demonstrate the thermal analysis and laser performance of a GYSGG/Cr,Er,Pr:GYSGG composite crystal. The lifetime ratio of lower and upper levels of Er in Cr,Er,Pr:GYSGG crystal is further reduced due to the optimized doping concentrations. The thermal effect of composite crystal is lower than that of Cr,Er,Pr:GYSGG crystal.

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We demonstrate the growth, spectroscopy, and laser performance of a 2.79 μm Cr,Er,Pr:GYSGG radiation-resistant crystal. The lifetimes for the upper laser level (4)I(11/2) and lower laser level (4)I(13/2) are 0.

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Familial dyskeratotic comedones is a well-known genodermatosis with autosomal dominant inheritance, characterized by numerous comedones with dyskeratosis in histology and scar formation in consequence. In contrast, cases of familial disseminated comedones without dyskeratosis appear to be extremely rare. So far, only three reports could be found in the literature.

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Interactions between a cationic gemini surfactant, 1,2-ethane bis(dimethyldodecylammonium bromide) (designated as 12-2-12), and a nonionic polymer polyvinyl alcohol (PVA) were investigated by means of viscosity and specific conductance. Results show that PVA displays special viscosity behavior in aqueous solutions containing the gemini surfactant 12-2-12, which is due to the molecular interaction of the polymer and the surfactant. It was found that the special viscosity depended on ionization of the surfactant, as well as polymer concentration and surfactant concentration in the nonionic polymer-surfactant system.

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