Effect of irradiation on Ti-doped sapphire by two different kinds of laser

分别采用波长为193 nm的ArF准分子激光与波长为800 nm、脉冲宽度为120 fs的飞秒激光对梯法生长的钛宝石进行辐照，并对辐照前后的吸收谱、荧光谱及电子顺磁共振（EPR）谱进行了检测。2种不同辐照的结果表明：218 nm及266nm吸收峰并不是完全由同一种色心所引起的。通过对比不同品质因数（FOM）值的钛宝石样品在420 nm处的荧光谱，发现准分子激光辐照后420 nm处荧光强度降低，表明样品中Ti~(4+)离子逍度降低。而在飞秒激光辐照下荧光强度增大，即Ti~(4+)浓度增大。根据2种激光的波长Ti-doped sapphire crystals were separately irradiated by ArF excimer laser with wavelength of 193 nm and femtose-cond laser with the wavelength of 800 nm. The spectra of absorption, fluorescence and electron paramagnetic resonance (EPR) were measured. The results show that the absorption peaks at wavelength of 218nm and 266nm are not attributed to same F~+ type color center. It is also found that between the different figure of merit for the crystals, the fluorescence intensity at wave-length of 420nm decreased after irradiate by excimer, it can be attributed to the Ti~(4+) ions change to Ti~(3+) , But during the femto-second laser irradiation, Ti~(3+) ions are changed to Ti~(4+) , and the fluorescence intensity increased. Explanations for different re-sults in two irradiation methods were made according to laser wavelength, power density and irradiation methods