Multiple-channel silicon micro-resonator based filters for WDM applications
Date of this VersionJune 2007
11 June 2007 / Vol. 15, No. 12 / OPTICS EXPRESS 7489
This document has been peer-reviewed.
We demonstrate predictable resonance wavelength shifts in silicon micro-resonators by varying their perimeters using high-resolution lithography. The linear coefficient between the resonance wavelength shifts and the perimeter changes is determined with detailed experiments, and found to be nearly constant across the C and L bands in telecommunications. This empirical coefficient is also compared to that obtained from simulations on straight waveguides. Based on the linear model, without post-fabrication trimming or tuning, an eight-channel wavelength de-multiplexer with reasonably predicted average channel spacing similar to 1.8 +/- 0.1 nm (3dB bandwidth similar to 0.7 +/- 0.1 nm) is demonstrated at telecommunication bands in a silicon chip for the first time. This filter has out-of-band rejection ratio similar to 40 dB, low channel crosstalk <= 30 dB and low channel dropping loss <= +/- 1 dB except for degraded performance in one channel due to fabrication imperfections.