You have misunderstood what I was referring to which is not helped by the fact that I was mistaken with what your design is doing. I thought you were using a Gaussian transverse profile which requires that the full width at 1/e^2 be larger than the source wavelength. Upon reviewing your design I do see that you are using a rectangular transverse profile, this does not have the same constraint, thought I do question why your field has only a 60nm half width.
Scott