Hello friend!
OLP switching is mainly based on the optical power difference between the working and protection channels.
There are several types of OLP protection, and the common type is OTS OLP/OMS OLP/OCH OLP/client OLP protection.
For client- and OCh-level OLP protection, you can configure OLP protection because it is not directly associated with OAs,
In the case of the OTS and OMS OLP protection, noise light may exist even if a fiber cut occurs. As a result, OLP switching may fail. Hence, OLP protection is not recommended.
I hope my answer will help you.