You can use this field to define the coating options.
For edge-coupled fibre/chips (typically with SSCs) you normally have different coating options provided by the foundry. In case you use InP or other active materials, you may also have special handling for laser facets.
If you use this field, then the OptoDesigner tech file will setup the coating options and write the designer spec in a side file. You can define which sides support coating; not setting the field will block coating for that edge.
For typical packaging rules (like defined by Europe's PIXAPP Pilot Line service) only West (typical photonics edge) and East (either photonics or RF) are the edges to use; with North and South for use by electrical (lower speed, few GHz) connections.
The values should be a list of names, seperated by a ,, so AR, NO,HR. The names are free, but preferred naming is:


This element does not have elements. The attributes are shown below, in a sorted per type fashion.

<techDefineCoating  East="..."  North="..."  South="..."  West="..." ... > ... </techDefineCoating>


The schema file can be downloaded or viewed at xPDK_OptoDesigner.