We present a dynamic pulse propagation modelling and experiments for femtosecond laser bonding of glass to glass/metal. The modelling provides quantitative estimates of the heat affected zone and weld geometry, incorporating the nonlinear electron dynamics along with temperature-dependent thermal properties. The model numerically determines the desired relative position between the geometrical focus of a femtosecond-laser-pulse and the interface of the two substrates to be welded, for the first time to our knowledge. The welding results of two similar and/or dissimilar materials using the model-predicted weld geometry and offset distance will be presented. This research was supported by NASA SBIR contract 80NSSC20C0432.
Ultrafast lasers enable non-contact, waste free, precise material removal. We have demonstrated single-digit nanometer precision polishing of optical material using a femtosecond laser. For ultrafast-laser-based waveguide writing, we study the underlying physics behind nonlinear optical dynamics during the femtosecond laser processing of crystalline materials. Unidirectional pulse propagation equation simulation is carried out to study the evolution of energy, fluence, plasma generation, and beam waist of a femtosecond pulse along the propagation direction under different energy and focusing conditions. Waveguides having a loss of 0.21 dB/cm are obtained. A Nd:YAG based waveguide laser with lasing threshold of 50 mw was demonstrated.