Optical frequency combs are a revolutionary light source for high-precision spectroscopy because of their narrow linewidths and precise frequency spacing. Generation of such combs in the mid-infrared spectral region (2-20 mm) is important for molecular gas detection owing to the presence of a large number of absorption lines in this wavelength regime. Microresonator-based frequency comb sources can provide a compact and robust platform for comb generation that can operate with relatively low optical powers. However, material and dispersion engineering limitations have prevented the realization of an on-chip integrated mid-infrared microresonator comb source. Here we demonstrate a complementary metal-oxide-semiconductor compatible platform for on-chip comb generation using silicon microresonators, and realize a broadband frequency comb spanning from 2.1 to 3.5 mm. This platform is compact and robust and offers the potential to be versatile for use outside the laboratory environment for applications such as real-time monitoring of atmospheric gas conditions.
demonstrate the modulation of silicon ring resonators at RF carrier frequencies higher than the resonance line-width by coupling adjacent free-spectral-range (FSR) resonance modes. In this modulator scheme, the modulation frequency is matched to the FSR frequency. As an example, we demonstrate a 20 GHz modulation in a silicon ring with a resonance linewidth of only 11.7 GHz. We show theoretically that this modulator scheme has lower power consumption compared to a standard silicon ring modulator at high carrier frequencies. These results could enable future on-chip high-frequency analog communication and photonic signal processing on a silicon photonics platform. (C) 2014 Optical Society of America
We demonstrate gigahertz electro-optic modulator fabricated on low temperature polysilicon using excimer laser annealing technique compatible with CMOS backend integration. Carrier injection modulation at 3 Gbps is achieved. These results open up an array of possibilities for silicon photonics including photonics on DRAM and on flexible substrates. (C) 2013 Optical Society of America
We demonstrate photodiodes in deposited polycrystalline silicon at 1550 nm wavelength with 0.15 A/W responsivity, 40 nA dark current, and gigahertz time response. Subband absorption is mediated by defects that are naturally present in the polycrystalline material structure. The material exhibits a moderate absorption coefficient of 6 dB/cm, which allows the same microring resonator device to act as both a demultiplexing filter and a photodetector. We discuss the use of deposited silicon-based complementary metal-oxide semiconductor materials for nanophotonic interconnects. (C) 2010 Optical Society of America