Discussion Forum

Hi,

I've been wondering if anyone knows how to set-up Comsol to solve for waveguide ring resonator modes. I am used to solving for simple rectangular waveguides and for this I usually go to 2D space dimension, RF module, Perpendicular waves, Hybrid mode waves, Mode analysis. These modes have an electric field of the type E(x,y,z,t) = E(x,y) * exp(-i*b*z+i*w*t), and comsol solves for the propagation constant (eigenvalue) b and the eigenvector E(x,y).

However, my problem now is that I want to find the modes of a waveguide ring resonator; this is simply a straight waveguide wrapped around itself to form a ring. The cross section of the waveguide is the same, but now I want modes of the form E(x,y,z,t) = E(y,r,phi,t) = E(y,r) * exp(-i*m*phi+i*w*t).The structure can be formed by simply revolving about the y-axis; hence I thought to go in the axisymmetric space dimension of Comsol, but the RF module has no mode analysis for this option (only eigenfrequency analysis). Does anyone know how to make Comsol solve for these modes (which are leaky-complex by nature)?

Thanks a bunch,
David