掺钛宝石的光谱研究

SPECTROSCOPIC STUDY ON Ti^(3+)IONS IN Al2O3 CRYSTAL

用IFUS(Induction Field Up-shift Method)方法生长了浓度高,光学质量好的Ti:Al_2O_3单晶,通过测量Ti^(3+)离子的吸收,激发,荧光光谱以及荧光寿命,分析研究了Ti:Al_2O_3单晶的发光特性和发光谱随温度的变化,(τFluo=3.1μs,300K;β=[Ti^(3+)]/[Ti]=0.999,αm/αr=380,α488nm=9.5cm^(-1)。

Recent demonstration of the wavelength tunable Ti3+:A12O3 laser has led to increased interest in the growth and spectroscopic characters of Ti3+Al2O3 crystal. The characteristics of crystal depend on the growth method. Two key properties of these crystals are the concentration and optical absorption cross section of the Ti3+ ions. The single crystal having high concentration of Ti3+(0.3 wt%)and good optical quality,was grown with IFUS method(Induction Field Up-Shift Method). The absorption, polarized fluorescence spectra and lifetime were masured at 300K.Analysis of the fluorescence spectra of Ti3+ ions in A12O3 is made for the temperature ranged for 15K to 290K.The temperature dependence of fluorescence spectra of Ti3+-doped sappire is shown in Fig.6.Three zero-phonon lines (616,618 and 620nm)were observed at 15K. The fluorescence intensity was found to decrease with the increase of temperature as is shown in Fig.6. The peak wavelength and the width of the fluorescence spectra are increased with the increase of temperature.The fluorescence intensity curves for both and polarization were measured(A=780nm)and the polarized light had the largest intensity.The fluorescence lifetime was determined to be 3.1us at 300K.Blue-green absorption band Ti3+:Al2O3 is due to the vibronic broadened 2T2g-2E transition. The largest absorption peak wavelength is 488nm. The infrared absorption at 850nm is very small am/as =380,a488=9 .5cm-1,B=. The tuning range is from 0.6 to 0.95nm. The Ti3+-coped sapphire is a kind of very proising tunable laser crystal.