Tuning of resonance-spacing in a traveling-wave resonator device.

In this work a traveling-wave resonator device is proposed and experimentally demonstrated in silicon-on-insulator platform in which the spacing between its adjacent resonance modes can be tuned. This is achieved through the tuning of mutual coupling of two strongly coupled resonators. By incorporating metallic microheaters, tuning of the resonance-spacing in a range of 20% of the free-spectral-range (0.4nm) is experimentally demonstrated with 27mW power dissipation in the microheater. To the best of our knowledge this is the first demonstration of the tuning of resonance-spacing in an integrated traveling-wave-resonator. It is also numerically shown that these modes exhibit high field-enhancements which makes this device extremely useful for nonlinear optics and sensing applications.