Jaymin Amin

Spectroscopy of doped lithium niobate

The values of measured and calculated spectroscopic quantities of lithium niobate doped with rare earth and transition metal ions, such as polarized emission and absorption cross sections, variation of fluorescence life time with temperature and concentration of the dopant, Judd- Ofelt coefficients, non-radiative transition probabilities and energy levels are presented. Wherever published data is available, comparison with measured or calculated data presented in this work is carried out. The theories utilized in the interpretation of the experimental results, such as Judd-Ofelt theory, Fuchtbauer-Lademburg relation and McCumber theory are summarily presented.

Optical amplification in localized doping of Er:Ti:LiNbO3 waveguides

An investigation on optical amplification in Ti waveguides in LiNbO3 doped with Er ions by thermal diffusion of thin metallic stripes is presented. The possibility of fabricating efficient optical amplifiers in LiNbO3 substrates realized by localization of the dopant on surface areas of the crystals was theoretically evaluated and the feasibility of fabricating efficient amplifiers in such doped structures was experimentally verified. It was concluded that the localized doping technique allows optimization of amplifier performance through adjustment of the active region geometry to the mode intensity profile.

Modeling of laser emission at 0.9 μm in Nd:LiNbO 3

Modeling of laser oscillation at 0.9 micrometers in Ti waveguides in LiNbO3 doped with Nd ions is presented. Laser emission at 0.9 micrometers in Ti waveguides in Nd:LiNbO3 crystals was recently demonstrated. However, lasing was reported as unstable and lasting only a few seconds, with parasitic lasing at the higher gain transition at 1.08 micrometers shown to be a problem. In this work the possibility of obtaining efficient and stable laser oscillation at 0.9 micrometers in Ti:LiNbO3 waveguides, fabricated in substrates doped with Nd ions by thermal diffusion of thin metallic stripes or planar thin films, was theoretically evaluated. It was concluded that emission at 0.9 micrometers , with complete suppression of the parasitic emission at 1.08 micrometers , should be possible by selective increase of the losses at 1.08 micrometers , through optimization of waveguide and laser cavity, spatia localizations of the Nd ions and the use of the dependence on polarization of the emission cross sections at 0.9 and 1.08 micrometers .