Surface-mount sapphire interferometric temperature sensor

Abstract

A fiber-optic high-temperature sensor is demonstrated by bonding a 45°-polished single-crystal sapphire fiber on the surface of a sapphire wafer, whose optical thickness is temperature dependent and measured by white-light interferometry. A novel adhesive-free coupling between the silica and sapphire fibers is achieved by fusion splicing, and its performance is characterized. The sensor's interference signal is investigated for its dependence on angular alignment between the fiber and the wafer. A prototype sensor is tested to 1170°C with a resolution of 0.4°C, demonstrating excellent potential for high-temperature measurement.

ZrO2 thin-film-based sapphire fiber temperature sensor

“…A thin film temperature sensor was constructed by fusion splicing [13] of the uncoated end of the sapphire fiber to a multi-mode silica fiber pigtail and connected to the optical interrogation system, as illustrated in Fig. 5.…”

Optical Fiber Sensors for High-Temperature Monitoring: A Review

“…The large diameter and highly multimode nature of sapphire inhibit the migration from silica fibers to sapphire fibers in conventional interferometry [ 103 ]. Over the years, researchers have initially realized the fabrication of sapphire FPI using different fiber fusion [ 104 , 105 , 106 , 107 , 108 ], sapphire wafer fusion [ 109 , 110 , 111 , 112 ], and metal coating [ 113 , 114 , 115 , 116 ]. Fabry–Perot interferometric sensors can be divided into two main groups: intrinsic FPI (IFPI)and extrinsic FPI (EFPI) [ 63 ].…”

Fabrication and Application of Single Crystal Fiber: Review and Prospective

“…Sapphire fiber sensors derived from Fabry Perot (FP) and Fiber Bragg Gratings (FBGs) are the most common ones, for example those which are developed at the Center for Photonics Technology (CPT), Virginia Tech. [ 50–54 ] Recently, Raman‐based distributed temperature sensing (DTS) and radiation sensing with sapphire fiber have also attracted great interest. Sapphire fibers are also used for medical power delivery systems at 2.936 µm where silica fibers are highly absorbing.…”