The port and node system

One of the key structural improvements made to Finesse is the introduction of a flexible port and node system. This system underpins the code structure of Finesse as all couplings and interactions are performed via ports and nodes of components.

A Port in Finesse 3 is fundamentally similar to the definition of a node in Finesse 2; i.e. it represents a point of connections between components in a model. Each port then has single or multiple nodes. There are three types of ports/nodes in Finesse 3, Optical, Electrical, and Mechanical (see NodeType) - Finesse 2 only had optical which limited the type of simulations that were possible. Nodes (Node) at each port always have the same type as the port itself. Each node represents a state of the optomechanical system we are modelling. Mathematically this means that each node corresponds to a particular linear equation in the linear set of equations that describe the behaviour of the system we are modelling.