Visible dual-wavelength light generation in optical superlattice Er:LiNbO[sub 3] through upconversion and quasi-phase-matched frequency doubling.

Optical superlattice Er:LiNbO[sub 3] was fabricated by inducing a periodic ferroelectric domain structure into the crystal during the growing process. Because of the combination of the nonlinear optical properties of LiNbO[sub 3] and the spectral properties of Er[sup 3+], the crystal can simultaneously emit the second harmonic light through quasi-phase matching and the green light through upconversion at room temperature. Pumped by infrared diode lasers, violet-and-green and blue-and-green light generation was demonstrated in two samples. The detailed absorption spectrum and emission spectrum of upconversion were measured. The possible physical mechanism was discussed. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]