TM_crossing

ofiber.TM_crossing(V, n1, n2, mode)[source]

Return the TM eigenvalue for a planar waveguide mode.

The eigenvalue, xi, satisfies the eigenvalue equation for the specified TM mode in a planar waveguide.

The solution is found numerically using the Brent method. The only tricky bit is setting the proper range to search within.

Parameters:

  • V – the V-parameter for the waveguide

  • n1 – index of waveguide

  • n2 – index of material next to waveguide

  • mode – desired propagation mode

Returns:

the eigenvalue. Returns 0 if no eigenvalue.