In photonic integrated circuit design, circuit designers need component models
that accurately describe the performance of the actual fabricated devices.
This allows the designer to be confident that their circuits will function properly once fabricated.
A Compact Model Library, or CML, contains custom models whose responses are calibrated
based on measured data from components fabricated using a specific foundry process.
CMLs are a part of a Process Design Kit, or PDK, which is a key piece
in the photonic integrated circuit design workflow.
A PDK provides all the required information for a circuit designer
to produce a design based on a given foundry process,
and it includes the CML which provides the simulation models, component geometries for layout,
design rules for design verification, and process variability data.
CMLs will be covered in more detail in the next section of the course,
and if you'd like to learn more about the photonic integrated circuit design workflow,
you can also refer to the related links below this video.
In this section of the course, we will cover S-parameter elements, compound elements,
and scripted elements which are useful for creating custom models.
S-parameter elements can load data files with data about the frequency-dependent complex transmission.
This data could also be the measured response of a fabricated component provided by a foundry.
Compound elements enable the design of arbitrarily complex circuits by grouping elements
and introducing hierarchy in the schematic representation of the circuit.
This is critical as photonic integrated circuits are being designed
with increasing complexity and increasing numbers of components.
Scripted elements provide flexibility for modelling parameterized functionalities
by using user-defined parameters and scripts to set properties, load data,
define data to send to output ports of the element, and to return custom results.