Optical sensor having a capillary tube and an optical fiber in the capillary tube

摘要

A system for use in a well includes an optical cable for positioning in the well. An optical sensor is optically coupled to the optical cable, where the optical sensor has a capillary tube and an optical fiber in the capillary tube. The capillary tube also includes a first sealed region containing a metallic material that is in liquid form at a downhole temperature in the well. A joint mechanism may attach the optical sensor to the optical cable.