Research on Thermal Stability of SOI Ring Resonator

As the core sensitive unit of optical waveguide gyro, SOI optical waveguide resonator has attracted much attention due to its micrometer size and high quality factor. In order to reduce the influence of temperature change on the performance of SOI micro-ring resonator, the thermal stability of the microring resonator is studied, and the single ring, cascaded double ring and three-ring microcavity structures based on silicon on insulator are designed and fabricated. The prepared micro-ring resonator was heated by the digital temperature control heating system, and the resonator resonance curve was obtained by using the laser wavelength scanning method. Through linear fitting analysis, the relationship between the resonant wavelength drift and temperature of the single ring, cascade double ring and three-ring resonators was calculated as <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$111 \text{pm} /{ }^{\circ} \mathrm{C}, 90 \text{pm} /{ }^{\circ} \mathrm{C}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$77 \text{pm} /{ }^{\circ} \mathrm{C}$</tex> respectively. The experimental results show that with the increase of the number of rings, the temperature coefficient of the resonator decreases and the temperature stability increases. The experimental results provide a certain basis for the subsequent research on the thermal stability of the optical waveguide gyro.