The growth of Cr4+: YAG and Cr4+: GGG thin films by pulsed laser deposition

The Cr.Ca:Y3Al5O12 (YAG) epitaxial thin films on YAG substrate have been fa bricated by pulsed laser deposition (PLD) method. The chemical shifts of ch romium ions in the Cr.Ca:YAG thin films is measured by X-ray photoelectron spectroscopy as a function of oxygen partial pressure in the PLD chamber. B y measuring the fluorescence intensity of Cr4- ions in Cr doped YAG thin fi lms, it is found that the addition of Ca2- ions as a charge compensator und er oxygen background pressure increases the active Cr4- ion fraction in the YAG thin film. The oxygen partial pressure of 2 mTorr is found optimum to maximize the Cr4+ number density in the Cr.Ca:YAG thin film. The Cr.Ca:GGG epitaxial thin film also shows the dependence of Cr4+ fluorescence on the o xygen partial pressure during deposition. (C) 2001 Elsevier Science B.V. Al l rights reserved.