Photonic and Thermal Modelling of Microrings in Silicon, Diamond and GaN for Temperature Sensing

• Published in: Nanomaterials (Basel, Switzerland) Switzerland), 2020-05, Vol.10 (5), p.934
• Main Authors: Weituschat, Lukas Max, Dickmann, Walter, Guimbao, Joaquín, Ramos, Daniel, Kroker, Stefanie, Postigo, Pablo Aitor
• Format: Article
• Language: English
• Subjects: Absorption; Absorptivity; Accuracy; Computer simulation; diamond; Diamonds; Finite element method; finite-element-simulation; Gallium; gallium nitride; Gallium nitrides; Heating; Influence; Mathematical models; Measurement techniques; optical ring resonator; Optics; Resistance thermometers; Resonance; Silicon; Simulation; Spatial discrimination; Spatial resolution; Temperature measurement; Temperature requirements; temperature sensor; Thermal analysis
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano10050934

Staying in control of delicate processes in the evermore emerging field of micro, nano and quantum-technologies requires suitable devices to measure temperature and temperature flows with high thermal and spatial resolution. In this work, we design optical microring resonators (ORRs) made of different materials (silicon, diamond and gallium nitride) and simulate their temperature behavior using several finite-element methods. We predict the resonance frequencies of the designed devices and their temperature-induced shift (16.8 pm K for diamond, 68.2 pm K for silicon and 30.4 pm K for GaN). In addition, the influence of two-photon-absorption (TPA) and the associated self-heating on the accuracy of the temperature measurement is analysed. The results show that owing to the absence of intrinsic TPA-processes self-heating at resonance is less critical in diamond and GaN than in silicon, with the threshold intensity I th = α / β , α and β being the linear and quadratic absorption coefficients, respectively.