This paper gives a report on the growth of saturable-absorber Cr, Ca: YAG by LPE. The analysis of the transmission spectra of epitaxially grown Cr, Ca: YAG shows that Cr4+ concentration ratio to total Cr concentration increase inversely as the concentration ratio of Ca and Cr decrease to Ca/Cr≈1. The transmission variation DT at 1.06 mm was measured to range between 5% and 30% according to the Cr concentration and the thickness of the epilayers. A discussion on the origin of a new absorption band at 760nm is also presented, which suggests that Cr5+ ion could exist in the Cr, Ca: YAG in addition to Cr3+ and Cr4+. ©2002 Elsevier Science B.V. All rights reserved.