Optical fiber for temperature sensing, and system and method for measuring temperature

A method of measuring temperature, the method comprising:

• positioning an optical fiber in contact with an object or in an environment having a temperature to be determined, the optical fiber comprising a core surrounded by a cladding, the core comprising an alkaline-earth fluorosilicate glass including defects, and the cladding comprising a silica glass;
• supplying infrared light to the optical fiber, thereby electronically exciting the defects;
• detecting green light emitted from the defects as a consequence of the electronic excitation;
• and
• determining an intensity value of the green light;
• and
• using calibration data to convert the intensity value of the green light to a temperature value for the optical fiber, thereby determining the temperature of the object or the environment.

A method of making an optical fiber, the method comprising:

• inserting a powder consisting of an alkaline earth metal and fluorine into a silica tube;
• after inserting the powder, heating the silica tube to a temperature sufficient to induce melting of the powder;
• drawing the silica tube to form a drawn cylindrical body including a molten core region in which diffusion and/or chemical reactions occur, leading to defect formation;
• and
• cooling the drawn cylindrical body to solidify the core, thereby forming an optical fiber, the core comprising an alkaline-earth fluorosilicate glass including defects, and the cladding comprising a silica glass.