The performance of a flashlamp pumped miniature 2.94 μm Er:YAG laser is optimized by using a mathematical model.
The model is based on the rate equations with spectroscopic data including energy transfer processes. Using this model,
we can explain the experimental phenomenon that the laser pulse slightly extends beyond the pumping pulse in some
cases. A method of optimizing the reflectivity of the output coupler was also presented.
A scheme capable of demonstrating shift- and rotational-invariant associative memory is presented. The scheme can be implemented both digitally and optically. In optical implementation, we use one holographic spatial frequency filter and one ordinary hologram of the reference pattern. A BaTiO3 crystal is also employed in the experiment. In the digital implementation of the scheme, in addition to the rotational invariance it is shift invariant too. However, the optical implementation exhibits shift invariance only when the BaTiO3 crystal is sufficiently large.