Programming a Double Pinhole Transmission Function

In this programming example we illustrate how to code a transmission function that imitates an opaque screen punctured by two round holes. The snippet can be also be used as a source, if the interaction between the incoming field and the perforated screen is not of interest (for instance, if the apertures for the two pinholes are always assumed to be completely filled by the input field). Please bear in mind that there may be more efficient ways to simulate such an optical setup; the main purpose of this document is to act as a programming example.