Experimental study of a thermochromic material based optical fiber sensor for monitoring the temperature of the water in several applications

This paper describes the use of a thermochromic material (2,4,5-triphenylimidazole or also called Lophine) for the fabrication of temperature optical fiber sensors. First, an experimental study of this material at different temperatures is presented and subsequently its behavior in two different schemes (variations of the reflected optical power and of the transmitted optical power) is analyzed. The characterization of both low cost sensors is discussed comparing the experimental results and analyzing their advantages and disadvantages. Besides, all the measurements taken were immune to humidity obtaining ideal sensors for monitoring the temperature of the water in several applications.