掺Nd^(3+)硼硅酸盐玻璃的非线性光学特性

Nonlinear Optical Performance of Nd^(3+)-Doped Borosilicate Glass

在调Q纳秒Nd:YAG强激光脉冲下,使用闭孔Z-扫描技术研究了硼硅酸盐基质玻璃及其掺Nd3+玻璃的三阶光学非线性特性。发现基质玻璃具有正的三阶非线性折射系数和非线性吸收系数,属于自聚焦反饱和吸收型的光学介质;而随着Nd3+的掺入,该硼硅酸盐玻璃的三阶非线性折射和吸收系数较基质玻璃有明显的增大,远高于一个量级。用开孔Z-扫描实验与光限幅实验进一步验证了掺Nd3+玻璃具有较高的三阶非线性吸收系数,表明Nd3+的掺入提高了硼硅酸盐玻璃在532 nm处的激光防护性能。

The third - order optical nonlinearities of the borosilicate glass and two types of Nd^3 ＋ -doped glass are measured by the closed - aperture Z - scan technique using Qnanosecond Nd ： YAG third - order laser pulses. It is found that the matrix glass possesses a positive nonlinear refractive index and a positive nonlinear absorption coefficient, belonging to self - focus antisaturation optical medium. Both the third - order nonlinear refractive index and absorption coef- ficient of Nd^3 ＋ - doped glasses are one order larger than those of the matrix glass with the additim of Nd^3 ＋. Also, an open - aperture Z - scan experiment and an optical limiting experiment further tell us that the Nd^3 ＋ - doped glass has a high third - order nonlinear absorption coeffi- cient, which indicates that Nd^3＋ -doped glasses are provided with a good protection performance for the 532nm -laser.