D. Scarano et I. Montrosset, TRANSVERSAL MODE COMPETITION IN ERBIUM-DOPED TI-LINBO3 WAVE-GUIDE LASERS, IEEE journal of quantum electronics, 32(4), 1996, pp. 628-637
Theoretical modeling of Erbium-doped LiNbO3 waveguide lasers has been
developed considering the competition between q-TM and q-TE signal mod
es, Two different approaches have been used: the first is based on the
mean field approximation for signal and pump power and for population
inversion, the second takes into account the longitudinal distributio
n of the pump power and of the population densities, Our formulation t
akes into account, for the first time, the competition between orthogo
nally polarized modes, evaluating the transversal overlap between the
fields and the population inversion, the effects of double pass for th
e pump, the signal and pump saturation effects, the stimulated emissio
n also at pump wavelength, the wavelength dependent cross sections and
mirror reflectivities. A diffused dopant distribution in depth and un
iform in lateral direction have been used, A q-TM or q-TE pump mode ar
ound 1.48 mu m has been considered, The threshold pump power optimizat
ion has been performed changing the dopant profile diffusion depth and
maximum surface concentration, The results show how, above threshold,
various types of output power characteristics, experimentally found,
are due to the different transversal saturation of q-TM and q-TE lasin
g modes.