Transitioning from resistance devices to photonic devices for temperature measurements

For the past century, industrial temperature measurements have relied on resistance measurement of a thin metal wire or filament whose resistance varies with temperature. Though resistance thermometers can routinely measure industrial temperatures with uncertainties of 10 mK, they are sensitive to mechanical shock which causes the sensor resistance to drift over time requiring frequent off-line, expensive, and time consuming calibrations. These fundamental limitations of resistance thermometry have produced considerable interest in developing photonic temperature sensors to leverage advances in frequency metrology and to achieve greater mechanical and environmental stability. We are developing a suite of photonic devices that leverage advances in microwave and C-band light sources to fabricate cost-effective photonic temperature sensors. Our preliminary results indicate that using photonic devices such as the ring resonator we can measure short term temperature fluctuations of 80 μK at room temperature. Photonic sensor technology provides a low cost, lightweight, portable and electromagnetic interference (EMI) resistant solution which can be deployed in a wide variety of settings ranging from controlled laboratory conditions, a noisy factory floor, advanced manufacturing, to the variable environment of a residential setting.