On-chip silicon waveguide Bragg grating photonic temperature sensor

Abstract

Resistance thermometry is a time-tested method for taking temperature measurements. In recent years, fundamental limits to resistance-based approaches have spurred considerable interest in developing photonic temperature sensors as a viable alternative. In this study, we demonstrate that our photonic thermometer, which consists of a silicon waveguide integrated with a Bragg grating, can be used to measure temperature changes over the range of 5°C-160°C, with a combined expanded uncertainty [k=2, 95% confidence level] of 1.25°C. Computational modeling of the sensor predicts the resonance wavelength and effective refractive index within 4% of the measured value.

Optical temperature sensor with enhanced sensitivity by employing hybrid waveguides in a silicon Mach-Zehnder interferometer

“…Linear fittings are also shown to obtain the temperature sensitivities, which are extracted to be 172 pm/°C and 70 pm/°C for the proposed and the reference temperature sensors, respectively. The measured sensitivity of the all-silicon reference temperature sensor agrees well with previous reports [16][17][18]. Considering the effect of the two tapers with L t = 20 μm, the calculated temperature sensitivity is 163 pm/°C, which agrees well with the measured sensitivity.…”

“…So far, the most accessible method for measuring the temperature is still resistance thermometry, in which a metal's resistance varies with the temperature. However, given its problem of being sensitive to electromagnetic interference (EMI), humidity, and mechanical shocks, resistance thermometers' territory is being seized by sensors utilizing other methods, among which optical temperature sensors are attracting substantial interests [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Optical temperature sensors have been demonstrated in fibers inscribed with Bragg gratings [6,7] and in configurations of Mach-Zehnder Interferometers (MZIs) [8,9], or e.g.…”

“…utilizing graphene [10]. Integrated optical sensors on silicon [11][12][13][14][15][16][17][18][19][20][21] have also been demonstrated and are foreseen to be promising candidates for integration with electronic circuits for on-chip signal processing and calibration compared with their fiber-optic counterparts. Furthermore, the large thermo-optic coefficient (TOC) of silicon (~1.86 × 10 −4 /°C [22]) suggests a large temperature sensitivity of the temperature sensor, which is usually preferred in a temperature sensor employed in many chemical or biological processes that may behave distinctively different at small temperature variations [4].…”

“…Diverse silicon photonic structures have been utilized to achieve temperature sensors, including ring resonators [11][12][13][14][15], Bragg reflectors [16,17], Fabry-Perrot (FP) cavities [18], and interferometers [19][20][21]. However, the temperature sensitivity of above demonstrated sensors are typically limited to ~80 pm/°C.…”

Experimental demonstration of a reconfigurable electro-optic directed logic circuit using cascaded carrier-injection micro-ring resonators

“…Currently, silicon photonics has achieved great development in many fields, and various silicon-based optical devices have been demonstrated successfully such as filters 7–9 , routers 10–12 , lasers 13–17 , multiplexers 18–22 , sensors 23–27 , electro-optic modulators 28–38 and optical logic devices 39–45 , etc. Being a kind of basic devices in the area of silicon photonics, micro-ring resonator (MRR) is widely used in high-performance computing and optical information processing due to its unique advantages such as sharp resonances for wavelength selectivity, compact size, low consumption, and large-scale integration.…”