RESUMEN
The ever-increasing global network traffic requires a high level of seamless integration between optical interconnect systems and complementary metal-oxide-semiconductor (CMOS) circuits. Therefore, it brings stringent requirements for future electro-optic (E-O) modulators, which should be ultracompact, energy efficient, high bandwidth, and in the meanwhile, able to be directly driven by the state-of-the-art CMOS circuits. In this Letter, we report a low-voltage silicon photonic crystal nanocavity modulator using an optimized metal-oxide-semiconductor (MOS) capacitor consisting of an In2O3/HfO2/p-Si stacked nanostructure. The strong light-matter interaction from the accumulated free carriers with the nanocavity resonant mode results in holistic improvement in device performance, including a high tuning efficiency of 250 pm/V and an average modulation strength of 4 dB/V with a moderate Q factor of â¼3700 and insertion loss of â¼6 dB using an ultrashort electrode length of only 350 nm. With 1 V driving voltage over a capacitive loading of only 13 fF, the silicon photonic nanocavity modulator can achieve more than 3 dB extinction ratio with energy consumption of only 3 fJ/bit. Such a low-voltage, low-capacitance silicon nanocavity modulator provides the feasibility to be directly driven by a CMOS logic gate for single-chip integration.
RESUMEN
Naphthalene-linked P2-P4 macrocycles within a tri-peptide-based acyl sulfonamide chemotype have been synthesized and found to inhibit HCV NS3 proteases representing genotypes 1a and 1b with single digit nanomolar potency. The pharmacokinetic profile of compounds in this series was optimized through structural modifications along the macrocycle tether as well as the P1 subsite. Ultimately a compound with oral bioavailability of 100% in rat, and a long half-life in plasma was obtained. However, compounds in this macrocyclic series exhibited cardiac effects in an isolated rabbit heart model and for this reason further optimization efforts were discontinued.