Lumerical photonic Verilog-A models are designed to enable multi-mode, multi-channel, and bidirectional optical signal modeling. This documentation describes the optical port configuration standard for Lumerical photonic Verilog-A models.
Signal discipline
In our photonic Verilog-A models, bidirectional optical signal is encoded by using both potential and flow of the “electrical” discipline.
Optical port configuration for single-channel model
Optical signals are complex and mode-dependent. Accordingly, the optical port is defined as a bus consisting of 4 electrical lines:
- [0]: the real part of the complex amplitude, for model 1;
- [1]: the imaginary part of the complex amplitude, for mode 1;
- [2]: the real part of the complex amplitude, for model 2;
- [3]: the imaginary part of the complex amplitude, for mode 2;
Each electrical line is bidirectional.
Wavelength for the optical signal propagating through lines [0] to [3] is controlled by a global design variable, wavelength1. And its parameter value is used to characterize wavelength-dependent model behavior.
The single-channel model supports 2 independent modes.
Optical port configuration for multi-channel model
To support modeling multiple wavelength channels, the bus can be extended by adding more copies of the above 4 electrical lines. The total number of bus lines is 4xN, where N is the number of wavelength channels. Each wavelength-channel supports 2 optical modes.
Here is an example for a 2-channel optical port configuration:
- [0]: the real part of the complex amplitude, for model 1 at wavelength channel 1;
- [1]: the imaginary part of the complex amplitude, for mode 1 at wavelength channel 1;
- [2]: the real part of the complex amplitude, for model 2 at wavelength channel 1;
- [3]: the imaginary part of the complex amplitude, for mode 2 at wavelength channel 1;
- [4]: real part of the complex amplitude, for model 1 at wavelength channel 2;
- [5]: the imaginary part of the complex amplitude, for mode 1 at wavelength channel 2;
- [6]: the real part of the complex amplitude, for model 2 at wavelength channel 2;
- [7]: the imaginary part of the complex amplitude, for mode 2 at wavelength channel 2;
Wavelengths for the N-channel optical signals are controlled by global design variables, wavelength1, wavelength2, …, wavelength<N>. Models with wavelength-dependent performance are characterized based on wavelength<N> values.
The number of wavelength channels, N, is user-defined through parameter NumOfChannel
in the library master file. For more information, release refer to Library Master File page.