Powder synthesis and spectroscopic properties of ytterbium-doped yttrium oxysulfide

Ytterbium-doped yttrium oxysulfide(Yb:Y_2O_2S)has been synthesized by solid-state reaction with sulfide flux.Diffuse reflection and emission spectra have been measured in order to determine the crystal field splitting of Yb~(3 )ion in the YOS lattice.According to the crystal-field levels probed in the spectra,the crystal field splitting of ~2F_(7/2)manifold of Yb~(3 )ion in YOS is 709 cm~(-1),which is large enough for the quasi-three-level laser operation of Yb~(3 )ion.Emission peak position,width,full-width at half maximum (FWHM),and normalized intensity of Yb:YOS are fitted from its emission spectrum.For comparison, relevant data of 5.4 at.-% Yb:YAG is also provided.     

集成式双线阵立体测绘相机光学系统设计

针对双线阵立体测绘相机光学系统设计指标的要求,设计了一种三反离轴光学系统,并针对该光学系统的特点,对像质进行了分析.光学系统设计传递函数在0.6左右(在50lp/mm处),相对畸变小于3×10-4,校正绝对畸变小于20μm,相机在成像质量方面达到立体测绘的要求.同时,为了使相机在体积尺寸小、结构紧凑及轻量化等方面满足卫星平台的要求,采用了一种新型的光学系统布局,在减小双线阵立体测绘相机的体积、材料及减轻重量等方面,具有独特的优势;光学系统可以安装在同一机械结构体内,以利于采取有效的热控措施,将主镜以一定的交会角在同一基准上支撑、装调,所以它具有尺寸稳定性好,温度敏感度低等优点.