2005 Conference on Lasers and Electro-Optics Europe

Recent developments in Nd3+:Ba2NaNb5O15 non linear lasers:Tuneability and non collinear intracavity propagation

A. R6denas, D. Jaque and J. Garcia Sole

Grupo de Espectroscopia Laser, Departamento de Fisica de los Materiales, Facultad de Ciencias,Universidad Aut6noma de Madrid, Alfadrid 28049, Spain

F. Agull6-Rueda

Instituto de Ciencia de Materiales de AMladrid (CSIC, Cantoblanco, Madrid 28049, Spain

Neodymium doped Barium Sodium Niobate (Nd:Ba2NaNbO]5) (Nd:BNN) is an interesting self

frequency doubling laser crystal combining good laser properties and high nonlinear coefficients.

Furthermore, interesting non collinear propagation phenomena (isotropic, anisotropic and electro opticaldiffractions) have been demonstrated in periodically poled BNN crystals by taking advantage of the

periodic modulation in both refractive index and electro-optical coefficient. In this talk we report on the

main properties of periodically poled Nd3+ doped BNN crystals by using micro Raman, micro

luminescence and second harmonic experiments. These experiments have been used to elucidate the

relationship between growth striae, ferroelectric domain distribution and Nd3+ local concentration. We

will also show experimental evidence concerning the existence of a periodic modulation in the refractive

index caused at domain walls.

The spectroscopic properties ofNd3+ ions in BNN crystals have been studied in detail revealing

that the cationic disorder characteristic of BNN lattice leads to broad 4F3/2__4111/2 and 4F3/2_*4113/2emission bands and, therefore, to the possibility of tuneable laser light generation around 1.06 and 1.3

gm. Furthermore, due to the presence of self frequency doubling effects, the possibility of wavelengthselection in the infrared can be shifted to the green and red. We have experimentally demonstrated this

possibility from a diode pumped Nd:BNN laser.

We also report on effects caused by the periodic modulation of refractive index on the laser

performance of diode pumped Nd:BNN crystals. We will show how the main effect is the creation of a

periodic modulation in the spatial distribution of infrared and visible output radiation. This will be

explained in terms of bulk interference effects at domain walls. Finally we will show how the

combination of wavelength selection and non collinear intracavity propagation is a promising tool for an

acurete control of spatial distribution of laser radiation generated from diode pumped solid state lasers.

The results presented in this talk strongly encourage the study of the novel generation of selfactivated photonic crystals.

0-7803-8974-3/05/$20.00 ©2005 IEEE 66