Design, fabrication, and characterization of metal embedded microphotonic sensors

Recent developments in integrated microphotonics have led to unprecedented potential toward robust sensor enhancements for manufacturing systems. These micron-sized subwavelength structured photonic sensors could allow critical thermomechanical phenomena in manufacturing processes to be monitored while offering immunity to electromagnetic interference, resistance to hostile environments, multiplexing capabilities, and high rates of data collection. To implement these novel sensors into real manufacturing processes, the microphotonic sensors can be embedded at critical locations in metallic structures, which are heavily used in hostile manufacturing environments. This paper presents the study of design, fabrication, and characterization of integrated microring sensors. Various thin film optical materials were studied and single ring resonators were designed. A new approach to fabricate metal embedded microring sensors was developed. Metal embedded optical microring temperature sensors were characterized. The Q factor of the metal embedded microring sensors was measured to be around 2000, while the free spectral range was about 5.2 nm. The temperature sensitivity of the metal embedded microring sensor was 24.2 pm/degrees C.