Experimental Study of a Real-Time and Highly Sensitive Fiber-Optic Porous Silicon Temperature Sensing Probe

Abstract

We report the development of a temperature sensing probe created as a result of the combination of an optical fiber and a porous silicon microcavity (PSMC). After determining the physical parameters of the PSMC to achieve the required porous sensing structure, it was fabricated by electrochemically etching a silicon wafer. A 1-mm2 PSMC piece was attached to the tip of an optical fiber so that temperature variations can be monitored in real-time exactly on that point. First, the performance of the PSMC sensor probe was characterized in a stable environment as water, obtaining a sensitivity around 110 pm/°C and a resolution in the 10-4 °C range. Afterward, the temperature transmission dynamics in air environment were studied.