Silicon photonic components on the COTTONTAIL chip

We report on characterization results for our new silicon photonic chip for high-speed data transmission, called COTTONTAIL (Chip for detector instrumentation with wavelength division multiplex). Modulation bandwidths of different travelling-wave Mach-Zehnder modulators and ring resonator modulators are sufficient for very high data transmission rates. Bit error rate measurements were conducted with a very low voltage swing of 1.1 V pp and error free transmissions could be established up to a data rate of 11.3 Gb/s with the ring modulators and up to 8.5 Gb/s with the Mach-Zehnder modulators. Wavelength filters for wavelength division multiplexing show a very low transmission loss of less than 2.3 dB with a slight wavelength shift of the filtering characteristics. Also included photodiodes are well suited for high speed downlinks with data rates in excess of 40 Gb/s or on-chip modulator monitoring.