Design of a single all-silicon ring resonator with a 150  nm free spectral range and a 100  nm tuning range around 1550  nm

We present a novel and simple method to obtain an ultra-wide free spectral range (FSR) silicon ring resonator together with a tuning range covering the entire spectrum from 1500 nm to 1600 nm.A ring resonator with a large FSR together with a high Q factor, high tuning efficiency, low fabrication cost and complexity is desired for many applications.In this paper, we introduce a novel way to make such a ring resonator, which takes advantage of the well known resonance-splitting phenomenon.It is a single ring resonator with a FSR more than 150 nm around 1550 nm and has an easy thermo-optic tunability which can produce a tuning range around 90 nm or even more.Moreover, the device is simple to implement and can be fabricated in standard CMOS technology without requiring any kind of complicated processing or extra materials.The potential applications include single mode laser cavities, WDM filters, (de)multiplexers, optical sensors and integrated reflectors.