Excited-state absorption in NdAl[sub 3](BO[sub 3])[sub 4] laser crystal.

We present an investigation in NdAl[sub 3](BO[sub 3])[sub 4] (NAB) crystal of the excited-state absorption (ESA) around the main laser lines (1060 and 1338 nm) by the so called excited-state excitation technique. The involved transitions are from the [sup 4]F[sub 3/2] level toward the [sup 4]G[sub 7/2]+[sup 4]G[sub 9/2]+[sup 2]K[sub 13/2] levels (1300–1400 nm range) or toward the [sup 2]G[sub 9/2]+[sup 4]G[sub 11/2]+[sup 2]D[sub 3/2]+[sup 2]K[sub 15/2] levels (1020–1100 nm range). We have performed the Judd–Ofelt analysis extended to anisotropic crystals in order to get the cross sections (cm[sup 2]). In each case, the ESA peaks do not coincide with the laser emission ones, but a reduction of the effective laser emission cross section is observed at 1338 nm. Finally, the values obtained from the application of the Judd–Ofelt formalism have been used to estimate the influence of ESA in the pumping domain on the laser performance. It has been found that its contribution is not significant, indicating that NAB is an excellent candidate for efficient high-power microchip lasers emitting at 1060 and 1338 nm. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]