Discussion Forum

I am attempting to simulate a 3D optical cavity formed by a ridge waveguide (i.e. like you would find in a ridge waveguide semiconductor laser). Using the 2D perpendicular wave application mode, I can find the transverse eigenmodes of the waveguide for a given frequency without any difficulty.

Now, given the propagation constant for this frequency I can determine how long the cavity would have to be in the z-direction to give a standing wave. I assumed that if I made a cavity of this length (with the same cross-section, of course) in the 3D electromagnetic eigenfrequency mode, set the ends of the cavity to be perfect electric conductors (i.e. mirrors), and solved for eigenfrequencies around the frequency of interest I would find a resonant mode.

However, all that I get is junk. Is my approach here fundamentally flawed? I know I should be able to simulate this type of cavity one way or another, but I'm clearly doing something wrong. My attempts to find a COMSOL model where someone simulates a waveguide cavity have been fruitless thus far. Has anyone tried something like this (even if it is just simulating a mode in some type of generic 3D Fabry-Perot cavity, since I can't seem to find any examples of that either)? How should I be going about this problem?