首先测量了ZBLAN:Yb^3+,Tm^3+分别在980nm和808nm激光激发下的400—600nm波段内的上转换发光光谱,在此基础上研究了980,808nm激光共激发下ZBLAN:Yb^3+,Tm^3+的上转换发光特性。在测量过程中,分别改变输入激光功率,测量了上转换发光强度与泵浦激光输入功率的关系,由此绘制双对数曲线图,对上转换发光机制进行了分析。研究证明980nm激发为三光子过程、808nm激发为双光子过程,而980,808nm激光共同激发为共协过程。
Under the excitation of 980 nm laser and 808 nm laser, the upconversion luminescence of ZBLAN:Yb^3+,Tm^3+ is detected. The mol fraction of Yb^3+,Tm^3+ is 3% and 1% , respectively. The emission of ZBLAN: Yb^3+,Tm^3+ is blue light with the peak at 476 nm which comes from ^1G4→^3H6 transition of Tm, no matter excited by 980 nm, 808 nm and both 980 nm and 808 nm , but the emission intensity is different. The emission intensity co-excited by both 980 nm and 808 nm is much stronger than that excited by 980 nm or 808 nm only. This phenomenon can be explained by luminescence mechanism. Under the excitation of 980 nm or 808 nm, the emission of 476 nm is three photon or two photon process, respectively, while in the 980 nm and 808 nm co-excitation system, the emission of 476 nm is due to one photon process.