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Ma X.,Beijing Opto Electronics Technology Co. | Ma X.,Beijing University of Technology | Wang Y.,Beijing Opto Electronics Technology Co. | Yao B.,Harbin Institute of Technology | And 2 more authors.
Zhongguo Jiguang/Chinese Journal of Lasers | Year: 2011

The causes of the floating-debris on the surface of Ho:Tm:YLF melt, the scattering particles and the crack of Ho:Tm:YLF crystal during the Czochralski growth are analyzed in this paper. Through elaborately designing of the symmetry temperature field, and adjusting temperature gradient and the crystal growth process parameters, the scattering particles and the crack of the crystal are eliminated effectively. The growth atmosphere with a certain volume CF 4 contributes to decreasing the floating-debris on the melt surface effectively, and the influence of the floating-debris on the normal crystal growth are overcome. By above technique ways, high-quality Ho:Tm:YLF crystals with the size of φ(25-30) mm×(100-120) mm are grown. The laser performance test of Ho:Tm:YLF crystal shows that under LD double-end-pumped conditions more than 10 W laser at 2.05 μm is achieved, and the laser slope efficiency reaches 41.2%, optical-to-optical efficiency reaches 36.4%.


Xia S.-X.,North China Research Institute of Electro Optics | Xia S.-X.,Beijing Opto Electronics Technology Co. | Mo X.-G.,Beijing Opto Electronics Technology Co. | Li X.-W.,Beijing Opto Electronics Technology Co. | And 5 more authors.
Rengong Jingti Xuebao/Journal of Synthetic Crystals | Year: 2013

The Fe2+:ZnSe crystal with the diameter of 20 mm and the thickness of 2.0 mm has been prepared by thermal diffusion doping technique. Based on the spectral measurement, the crystal sample shows that it has significant characteristic absorption peaks of the Fe2+:ZnSe crystal around 3.0 μm, and the relative absorption intensity approaches to nearly 85%. The iron ions doping concentration in the crystal sample is 4.5×1017 cm-3 which is detected by the Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The main factor impacting on iron ions doping concentration was investigated.


Li X.,Beijing Opto electronics Technology Co. | Zhang Y.,Beijing Opto electronics Technology Co. | Mo X.,Beijing Opto electronics Technology Co. | Wang Y.,Beijing Opto electronics Technology Co. | And 5 more authors.
Kuei Suan Jen Hsueh Pao/Journal of the Chinese Ceramic Society | Year: 2014

The transparent Nd3+:Y3Al5O12(Nd:YAG) ceramics with the size of 30 mm in diameter and 3.05 mm in thickness were fabricated by a composite sintering method (i.e., solid state reaction sintering and hot pressing post-treatment embedded in BN powders) with the commercial oxide powders as raw materials. The effect of hot pressing post-treatment embedded in BN powders on the optical properties, residual stress and optical uniformity of Nd:YAG ceramics was investigated. The results show that the application of the BN powders can solve the problem of crack and carbon contamination during hot pressing effectively. This method can reduce the residual pores in the ceramic body and improve the transmittance of Nd:YAG transparent ceramic. The transmittance of the Nd:YAG ceramic obtained is > 80%. The hot pressing post-treatment embedded in BN powder has no effect on the residual stress distribution and the optical homogeneity of Nd:YAG transparent ceramic. The laser performance of Nd:YAG ceramic sample was examined by a fiber-coupled 808 nm LD as a pump. It is indicated that the the CW laser output can be realized, the maximal output power is 3.6 W and the efficiency of optical to optical is 20%.


Li C.,Changchun University of Science and Technology | Zeng F.-M.,Changchun University of Science and Technology | Lin H.,Changchun University of Science and Technology | Zheng D.-Y.,Changchun University of Science and Technology | And 7 more authors.
Rengong Jingti Xuebao/Journal of Synthetic Crystals | Year: 2014

Nd:YAP and Tm:YAP crystals were grown by the Czoehralski method, which improves the crystal quality after vacuum annealing. The absorption and fluorescence spectra of Nd:YAP and Tm:YAP crystals were measured. Nd:YAP crystals have strong absorption in the vicinity of 808 nm, which matched emission wavelength of commercial laser diodes better, obtained the 1064 nm fluorescence output; Tm:YAP crystal has a certain absorption in the near 790 nm, the fluorescence peak at 1.87 μm corresponding to the 3F4→3H6 level transition , which is better for high energy Q output of laser.


Zheng D.,Changchun University of Science and Technology | Zheng D.,Beijing Opto Electronics Technology Co. | Fang X.,Changchun University of Science and Technology | Cui Y.,Changchun University of Science and Technology | And 4 more authors.
Kuei Suan Jen Hsueh Pao/Journal of the Chinese Ceramic Society | Year: 2014

Nd:LiYF4(Nd:YLF) polycrystalline raw materials were synthesized via high-temperature reactions between the rare earth oxides and anhydrous HF gas. The phase structure and the synthesis parameters of polycrystalline materials were analyized by X-ray diffraction. It is found that the existence of oxide impurities in rare earth fluoride as raw material has a great influence on the growth of crystals. The crystals grown with untreated fluoride raw material appear white inclusions on the crystal surface. The residual oxide impurities in the fluoride raw material can be removed after heat treatment at 1200°C in HF atmosphere, which can guarantee the quality of the growth crystal. The optimal component proportion of YLF crystal growth can be obtained at the LiF to YF3 mole ratio of 53:47. The Nd:YLF crystal was grown via the Czochralski method at the optimal component proportion. The results indicate that the Nd:YLF crystal has a high purity and superior optical properties. The main emission peaks of Nd:YLF crystal pumped under 808nm diode laser is located at 908 nm (4F3/2→4I9/2), 1047 and 1053 nm (4F3/2→4I11/2), and 1321 and 1313 nm (4F3/2→4I13/2), respectively.


Li H.-F.,Beijing Opto Electronics Technology Co. | Han J.-F.,Beijing Opto Electronics Technology Co. | Yang G.-L.,Beijing Opto Electronics Technology Co. | Mo X.-G.,Beijing Opto Electronics Technology Co.
Rengong Jingti Xuebao/Journal of Synthetic Crystals | Year: 2013

The Sm:YAG crystals with dopant concentration 3.0at%, 5.0at% and 10.0at% were grown by Cz method. The concentration of Sm ions in crystal was test with ICP-AES method, and the segregation coefficient was calculated with the result of Sm ions concentration. The growth condition for growing high dopant concentration was discussed, and the absorption spectra of crystals between visible light and near infrared were investigated. This absorption spectra show that the crystal has very weak absorption in the 800-900 nm range and has stronger absorption in the emitting wavelength of Nd:YAG crystal. The absorption coefficient is increased as the dopant concentration increasing. This study shows that Sm:YAG can be used for suppression of parasitic oscillations caused by the amplified spontaneous emission occurred during the working of high power Nd:YAG lasers.

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