Plasmonic modulator with >170 GHz bandwidth demonstrated at 100 GBd NRZ.

We demonstrate a plasmonic Mach-Zehnder (MZ) modulator with a flat frequency response exceeding 170 GHz. The modulator comprises two phase modulators exploiting the Pockels effect of an organic electro-optic material in plasmonic slot waveguides. We further show modulation at 100 GBd NRZ and 60 GBd PAM-4. The electrical drive signals were generated using a 100 GSa/s digital to analog converter (DAC). The high-speed and small-scale devices are relevant for next-generation optical interconnects.

Integrated optical frequency shifter in silicon-organic hybrid (SOH) technology.

We demonstrate for the first time a waveguide-based frequency shifter on the silicon photonic platform using single-sideband modulation. The device is based on silicon-organic hybrid (SOH) electro-optic modulators, which combine conventional silicon-on-insulator waveguides with highly efficient electro-optic cladding materials. Using small-signal modulation, we demonstrate frequency shifts of up to 10 GHz. We further show large-signal modulation with optimized waveforms, enabling a conversion efficiency of -5.8 dB while suppressing spurious side-modes by more than 23 dB. In contrast to conventional acousto-optic frequency shifters, our devices lend themselves to large-scale integration on silicon substrates, while enabling frequency shifts that are several orders of magnitude larger than those demonstrated with all-silicon serrodyne devices.

Plasmonic phased array feeder enabling ultra-fast beam steering at millimeter waves.

In this paper, we demonstrate an integrated microwave phoneeded for beamtonics phased array antenna feeder at 60 GHz with a record-low footprint. Our design is based on ultra-compact plasmonic phase modulators (active area <2.5µm2) that not only provide small size but also ultra-fast tuning speed. In our design, the integrated circuit footprint is in fact only limited by the contact pads of the electrodes and by the optical feeding waveguides. Using the high speed of the plasmonic modulators, we demonstrate beam steering with less than 1 ns reconfiguration time, i.e. the beam direction is reconfigured in-between 1 GBd transmitted symbols.

High speed plasmonic modulator array enabling dense optical interconnect solutions.

Plasmonic modulators might pave the way for a new generation of compact low-power high-speed optoelectronic devices. We introduce an extremely compact transmitter based on plasmonic Mach-Zehnder modulators offering a capacity of 4 × 36 Gbit/s on a footprint that is only limited by the size of the high-speed contact pads. The transmitter array is contacted through a multicore fiber with a channel spacing of 50 µm.

Plasmonic-organic hybrid (POH) modulators for OOK and BPSK signaling at 40 Gbit/s.

We report on high-speed plasmonic-organic hybrid Mach-Zehnder modulators comprising ultra-compact phase shifters with lengths as small as 19 µm. Choosing an optimum phase shifter length of 29 µm, we demonstrate 40 Gbit/s on-off keying (OOK) modulation with direct detection and a BER < 6 × 10(-4). Furthermore, we report on a 29 µm long binary-phase shift keying (BPSK) modulator and show that it operates error-free (BER < 1 × 10(-10)) at data rates up to 40 Gbit/s and with an energy consumption of 70 fJ/bit.

Low-power silicon-organic hybrid (SOH) modulators for advanced modulation formats.

We demonstrate silicon-organic hybrid (SOH) electro-optic modulators that enable quadrature phase-shift keying (QPSK) and 16-state quadrature amplitude modulation (16QAM) with high signal quality and record-low energy consumption. SOH integration combines highly efficient electro-optic organic materials with conventional silicon-on-insulator (SOI) slot waveguides, and allows to overcome the intrinsic limitations of silicon as an optical integration platform. We demonstrate QPSK and 16QAM signaling at symbol rates of 28 GBd with peak-to-peak drive voltages of 0.6 V(pp). For the 16QAM experiment at 112 Gbit/s, we measure a bit-error ratio of 5.1 × 10⁻5 and a record-low energy consumption of only 19 fJ/bit.

Polychlorinated biphenyls: penetration into the deep ocean by zooplankton fecal pellet transport.

High concentrations of polychlorinated biphenyls (PCB's) were found in fecal pellets from natural populations of euphausiids collected in the Ligurian Sea. Since biogenic particulate products, especially fecal pellets, are known to sink rapidly and intact to the ocean bottom, the transport of PCB's by such sinking particles could be an important mechanism which contributes to the penetration of PCB's into the deep sea.

Microwave plasmonic mixer in a transparent fibre-wireless link.

To cope with the high bandwidth requirements of wireless applications1, carrier frequencies are shifting towards the millimetre-wave and terahertz bands2-5. Conversely, data is normally transported to remote wireless antennas by optical fibres. Therefore, full transparency and flexibility to switch between optical and wireless domains would be desirable6,7. Here, we demonstrate for the first time a direct wireless-to-optical receiver in a transparent optical link. We successfully transmit 20 and 10 Gbit/s over wireless distances of 1 and 5 m at a carrier frequency of 60 GHz, respectively. Key to the breakthrough was a plasmonic mixer directly mapping the wireless information onto optical signals. The plasmonic scheme with its subwavelength feature and pronounced field confinement provides a built-in field enhancement of up to 90'000 over the incident field in an ultra-compact and CMOS compatible structure. The plasmonic mixer is not limited by electronic speed and thus compatible with future terahertz technologies.

Collection time again.

Looking forward to your next round of collection calls? Few of us do, yet collections play a vital role in every group practice, large or small. This crop of practical collection tips is guaranteed to boost the morale of everyone involved in the collection process. Not only are the basics of a good collection call set down, but result-getting responses to frequent debtor excuses are provided. Telephoning the debtor patient need not be a dreaded task. Just have confidence, keep in mind that the patient does owe you for services rendered in good faith, and pick up the phone--it's a snap!

Accounts receivable management techniques.

Here's what countless medical group administrators have been eagerly awaiting--the basics of good credit and collection techniques set down in a manner that makes them easy to understand and easy to adopt. Based on a survey of MGMA member groups, the author presents information on what administrators across the country are doing in an effort to collect money, and many "tricks of the trade" are shared here.