Changes in the refractive index of Ti:Al2O3 induced by 10-nsec, 532-nm pump pulses from a frequency-doubled Nd:YAG laser have been measured interferometrically at 632.8 nm for signal polarizations parallel (π) and perpendicular (σ) to the c axis. The nonthermal portion of these changes decays on a 3-μsec time scale characteristic of the fluorescence lifetime of Ti3+. For the σ polarization, the nonthermal index change is equal to the concentration of excited Ti3+ ions times (4 ± 2) × 10−24 cm3. The change for the π polarization is lower by a factor of 3.7 ± 0.6. The average change is consistent with the value estimated from a harmonic oscillator model that considers virtual transitions to a charge-transfer band.
© 1989 Optical Society of America
Original Manuscript: August 15, 1988
Manuscript Accepted: November 29, 1988
Published: January 15, 1989
K. F. Wall, R. L. Aggarwal, M. D. Sciacca, H. J. Zeiger, R. E. Fahey, and A. J. Strauss, "Optically induced nonresonant changes in the refractive index of Ti:Al2O3," Opt. Lett. 14, 180-182 (1989)