%0 Journal Article %J Optics Express %D 2010 %T Series-Coupled Silicon Racetrack Resonators and the Vernier Effect: Theory and Measurement %A Boeck, Robert %A Jaeger, Nicolas %A Rouger, Nicolas %A Chrostowski, Lukas %N 24 %P 7 %U http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-18-24-25151 %V 18 %X Silicon-on-insulator racetrack resonators can be used as multiplexers in wavelength division multiplexing applications. The free spectral range should be comparable to the span of the C-band so that a maximum number of channels can be multiplexed. However, the free spectral range is inversely proportional to the length of the resonator and, therefore, bending losses can become non-negligible. A viable alternative to increase the free spectral range is to use the Vernier effect. In this work, we present the theory of series-coupled racetrack resonators exhibiting the Vernier effect. We demonstrate the experimental performance of the device using silicon-on-insulator strip waveguides. The extended free spectral range is 36 nm and the interstitial peak suppression is from 9 dB to 17 dB. %8 11/2010