Subsea fiber optic sensor assemblies and related methods

A method comprising:

• (a) lowering a canister below a sea surface and into a subsea environment, wherein the canister defines a chamber that is maintained at a controlled pressure;
• (b) connecting an electrical connector defined on the canister to a subsea device;
• and
• (c) detecting a voltage or a current of the subsea device with a fiber optic sensing element that is positioned in the chamber.

A system comprising:

• a canister that defines a chamber and that is configured to maintain the chamber at a controlled pressure in a subsea environment;
• one or more connectors defined on the canister that are configured to be coupled to a subsea device;
• and
• one or more fiber optic sensing elements positioned in the chamber and coupled to the one or more connectors such that the one or more fiber optic sensing elements are configured to detect a plurality of electrical parameters of the subsea device via the one or more connectors.