We have developed a time dependent model for the eye-safe laser emission at 1.6&mgr;m, representing transitions from
the manifolds 4I13/2 to 4I15/2 of trivalent Er-doped YAG (Y<sub>3</sub>Al<sub>5</sub>O<sub>12</sub>). The model is based on a set of coupled first-order
differential equations (rate equations) that describe the laser kinetics of this quasi-three level laser system.
Also called zero-dimensional (0-D) equations, these equations are time only dependent with no spatial dimension
dependency. The model is anchored to experimental results including the experimental Stark levels that are
populated according to a Boltzmann distribution at room temperature. Emission cross section parameters are
calculated using reciprocity methods from experimental absorption cross sections. A MATLAB code is written and
the equations are solved numerically for output power and slope efficiency and threshold. The results are useful
with significant progress towards predicting the published experimental laser data. This model can be optimized for
its parameters such as output coupler reflectivity, ion concentration, etc and used for other hosts.
In this paper, we will present recent results from the first commercially available rotary disk laser. Rotary disk laser concept introduces physical motion as a new control element in solid state laser designs. Rotary disk lasers have the potential of producing much higher power in single-mode operation than other types of bulk solid state lasers. Rotary disk lasers also have the potential of generating much higher energy pulses than fiber lasers. The Nd-YAG rotary disk laser produced 30.8 W of output power in a single mode at 32.4% optical efficiency. In a preliminary test, 81.9 W was obtained from a single mode Yb-YAG rotary disk laser.
New solid-state passive Q-switch materials for the Er:glass laser at 1.53 micrometers are described. Saturable absorber Q-switching has been obtained using U<SUP>4+</SUP>:SrF<SUB>2</SUB>, Er<SUP>3+</SUP>:CaF<SUB>2</SUB>, and Er<SUP>3+</SUP>:Ca<SUB>5</SUB>(PO<SUB>4</SUB>)<SUB>3</SUB>F.