UV absorption wing enhanced refractive index changes observed in Yb:YAG and Yb:KGW

The authors confirmed the hypothesis that both excited-state absorption spectra in the near UV spectral domain and by performing new transient interferometric measurements, thus by using an He-Ne at 632 nm as a probe, but using the same kind of laser pump source for both experiments, i.e. a Q-switched Nd:YAG pumped OPO laser delivering 10 ns pulses of about 3 mJ around 970 nm. We also extended this investigation to the other well-known laser material Yb:KGW.