Measurement of saturation intensities in ion doped solids by transient nonlinear refraction

摘要

The transient response of the Z-scan signal △T(t) was used to investigate the nonlinearity of ion doped solids, n↓(2) measurements in ruby and alexandrite were performed using an Ar↑(+) laser. We observed that the nonlinearity response time τdecreases with the laser intensity asτ↑(-1) = τ↑ (-1) +I/l↓(s)),whereτ↓(0) is the excited state lifetime and Is the transition saturation intensity. So, by measuring the transient response at different laser intensities, we were able to determine not only the nonlinear complex refractive index n↓(2) but also τo and I↓(s) for Cr↑(+3) in ruby and in the two alexandrite sites. # 1997 American Institute of Physics. S0003-6951 (97)01007-3