Disclosed are interposer structures having an optical fiber connection and a related fiber optic ferrule that can form a portion of an optical assembly. The interposer structure is useful for transmitting optical signals to/from an integrated circuit that may be attached to the interposer. Specifically, the interposer structure and the related ferrule of the optical connector provide a passively aligned structure having a matched thermal response to maintain a suitable optical connection between the devices over a range of temperatures.