Session Q2 - Industrial Applications.
MIXED session, Wednesday afternoon, August 27
Room 175, Stevenson
The path of a laser through a non-isothermal gas is an integral component for using p-polarized reflectance spectroscopy to monitor the ultra-thin layers when growing advanced optoelectronic materials. The laser's incident angle (at the substrate) must match the Brewster angle (or pseudo-Brewster angle) for the best information about composition and growth rate. Here, we simulate gasdynamics inside a high-pressure Metal-organic chemical vapor deposition (MOCVD) reactor, and use this data to compute laser paths through the gas. Gasdynamics simulations are based on finite-element methods to model the temperature-dependent compressible flow. The gas density field is converted to the index of refraction using the Lorentz-Lorenz equation. The laser path is determined from a system of ordinary differential equations. Computations of the path under different conditions (e.g. for various time-slices) will be used to understand the transient effects induced by gasdynamics fluctuations.