I apologize for double-posting, but I can't seem to edit my question:
PS: Can you suggest any other way of modelling a wavelength-dependent modulator (the result should be some CM-compilable custom element with a specifiable "length" property, CW behaviour is the focus)?
So far, all the approaches I have come up have certain drawbacks and limitations. an overview:
Said Optical Time Variant SPAR element, but here the length of the modulator is fixed. To include Length, one would have to use a compound element (2 opt, 1 elec port) and then use the setup script to add such SPARs iteratively to the compound, say 500 * 10um SPARs for a 5mm long modulator.
Compound element (2 opt, 1 elec port) with rectangular bands Wavelength Demultiplexer, then an OM element for each wavelength band in parallel, then wavelength multiplexer. (obviously impractical)
Compound element (2 opt, 1 elec port) with a single OM element whose wavelength dependent complex effective index is created via setup script from a property "wavelength" of the compound element (the user has to specify this wavelength manually, since Interconnect compound element scripts cannot use popportframe("port") to obtain the input signal wavelength)
Compound element (2 opt, 1 elec port) with a Waveguide element (where wavelength dependence is easy) whose exact spectral effective index (or even MODE data file) is determined via script by an electrical input to the compound element. This would actually be really nice and would be my prefered approach, but there seems no simple way for the setup script of the compound element to get the data from the electrical input port...
an entirely scripted element ... I would really like to avoid this one...