a length of "rectangular geometry" waveguide,

a length of fibre,

a periodic repeat of another component - the sub-device is repeated N times for the modelling of codirectional couplers and the like,

a waveguide bent in an arc horizontally or even vertically by specified angle,

tapers - generic taper permits arbitrary definition of cross section at start and end of taper, plus a choice of linear, exponential or user defined taper functions - e.g. you can define a structure where lateral dimensions vary linearly, layer thicknesses vary exponentially and a layer refractive index varies according to your own tabulated function. The definition is sufficiently general that you can model more complex structures such as Y junctions using concatenated "taper" sections.

a simple joint, allowing horizontal and vertical offset of the joined waveguides, plus a fully general definition of horizontal and vertical tilt angle,

a free space joint (with Free Space Module), permitting propagation through air or any other uniform medium.