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Recent natural language reasoning models have achieved human-level accuracy on several benchmark datasets such as bAbI. While the results are impressive, in this paper we argue by experiment analysis that several existing attention-based models have a hard time generalizing themselves to handle name entities not seen in the training data. We thus propose Unseen Filler Generalization (UFG) as a task along with two new datasets to evaluate the filler generalization capability of a natural language reasoning model. We also propose a simple yet general strategy that can be applied to various models to handle the UFG challenge through modifying the entity occurrence distribution in the training data. Such strategy allows the model to encounter unseen entities during training, and thus not to overfit to only a few specific name entities. Our experiments show that this strategy can significantly boost the filler generalization capability of three existing models including Entity Network, Working Memory Network, and Universal Transformers.

Two channels of a ring modulator transceiver device are concurrently modulated and characterized for optical crosstalk by monitoring link bit error ratio. Power penalty of 1–3dB at +50GHz channel spacing is observed for 10Gb/s data rate.

A new silicon photonic platform on 310nm thick SOI wafers is presented. Process and layout optimizations for P-i-N ring modulators are described.

We identified significant spatial patterns in the wafer-scale process variation data of silicon microring modulators. These spatial patterns implicate some variation sources in certain fabrication process steps.

PAM-4 transmission is established by modulating two silicon ring modulators in series with two uncorrelated NRZ encoded data sources. The two modulators are thermally tuned to obtain different extinction ratios. 30Gb/s PAM-4 transmissions are achieved with only 1Vpp.

Optical switches based on ring resonator cavities are fabricated by a silicon photonics foundry process and analyzed for optical crosstalk at various data rates and channel spacing. An optical power penalty of 1 dB is measured for 40GHz channel spacing for 20Gb/s as compared to slower data rates.

We present a low-cost light-weight wristband Vital as the basic element for emergency response network, which senses and reports hazardous surroundings for people who need immediate assistance such as children and seniors. Based on a multi-sensor Arduino microsystem and a low-power Bluetooth 4.1 module [1], the Vital band samples data from multiple sensors and reports to a base station, such as the guardian's cell phone or the emergency response network, for an emergency situation. With a 3D-printed case and a lithium-ion coin battery, the Vital case is weighed 13 grams and sized 35 × 30 × 11 mm3. With 10 ms short sampling pulses and adaptive sampling rates, the estimated battery lifetime can be extended to more than 100 hours for activity tracking.

This paper examines the potential of silicon photonic microring resonator-based optical transceivers for compact wavelength-division multiplexing (WDM) optical interconnects. An overview of the photonic devices typically found in a ring resonator optical interconnect platform is provided and the design of transceiver circuits which address key challenges related to the modulators and drop filters is described. The possibility of further improvements in bandwidth density via efficient implementations of >50Gb/s PAM4 modulation with the microring modulators is detailed.

We demonstrate a high-speed carrier-injection silicon microring modulator operating at 20 Gb/s with 9 dB extinction ratio and 1.3 dB insertion loss using a pre-emphasis driving scheme. A SPICE-compatible dynamic model for the microring modulator is used to co-simulate with the pre-emphasis driver. The simulated optical eye diagrams agree well with the experimental results.

We demonstrate concurrent multi-channel transmission at 10 Gbps per channel of a DWDM silicon photonic transmitter. The DWDM transmitter is based on a single quantum dot comb laser and an array of microring resonator-based modulators.

Dense wavelength-division multiplexing (DWDM) is a promising technique to increase capacity of nanophotonic interconnects for chip-scale serial links. This paper describes recent progress in DWDM nanophotonic interconnects based on silicon microring resonators, including a five-channel DWDM transmitter using a quantum dot (QD) comb laser and carrier-injection modulators, as well as self-adaptive CMOS transmitter for hybrid CMOS and photonic chips integration.

Silicon microring modulators are critical components in optical on-chip communications. In this paper, we develop theoretical compact models for optical transmission, power consumption, bit-error-rate (BER), and electrical tuning of microring modulators. The proposed theoretical models have been extensively validated by fabricated devices from a number of designs and fabrication batches. Since the quality factor (Q) and the extinction ratio (ER) of the microring modulator are important to determine the BER and link power budget, we include accurate equations for the Q and the ER in our models. Based on the proposed models, we identify an extra power penalty for the electrical tuning, and an energy-efficient swing voltage for the microring modulator to achieve to minimum total energy consumption.

A Verilog-A carrier-injection ring modulator model accurately captures electrical and optical dynamics. The impact of pre-emphasis pulse duration, pulse depth, and DC bias is demonstrated with excellent matching between simulated and measured 8Gb/s eye diagrams.

We present energy-efficient microring resonator-based silicon photonic transceivers for DWDM optical interconnect.

Wavelength-division multiplexing (WDM) optical interconnect architectures based on microring resonator devices offer a low-area and energy-efficient approach to realize both high-speed modulation and WDM with high-speed transmit-side ring modulators and high-Q receive-side drop filters [1-3]. While CMOS optical front-ends have been previously developed that support data-rates in excess of 20Gb/s, these designs often do not offer the retiming and deserialization functions required to form a complete link [1,4]. Furthermore, along with the requirements of a sensitive energy-efficient receiver front-end with low-complexity clocking, wavelength stabilization control is necessary to compensate for the fabrication tolerances and thermal sensitivity of microring drop filters. In this work, a 24Gb/s hybrid-integrated microring receiver is demonstrated the incorporates the following key advances: 1) a low-complexity optically-clocked source-synchronous receiver with LC injection-locked oscillator (ILO) jitter filtering; 2) a large input-stage feedback resistor TIA cascaded with an adaptively-tuned continuous-time linear equalizer (CTLE) for improved sensitivity and bandwidth; 3) a receive-side thermal tuning loop that stabilizes the microring drop filter resonance wavelength with minimal impact on receiver sensitivity.

High efficiency operation of two types of quantum dot comb-laser is demonstrated at elevated temperature. Their energy efficiencies correspond to 0.6 pJ/bit at 12.5 Gbps and 1 pJ/bit at 25 Gbps at 80°C.

There has been significant recent interest in using the aggregate information from social media sites (e.g., Twitter) to identify influencers. To investigate this issue, one dynamic diversity-dependent algorithm is proposed for detecting the influencers by evaluating the influence of users throughout social networks. Comparative analyses with the existing methods on either synthetic social networks or real Twitter data show that our strategy performs best. It implies that the pattern of the influence propagation should be updated dynamically to reflect the flow of influence spread to better capture the rapidly changing dynamics of microblogs. Our proposed scheme is therefore practical and feasible to be deployed in the real world.

We present a DWDM silicon photonic transceiver with self-adaptive CMOS circuits. The energy efficiency is 808fJ/bit at 5Gbps for a ring-modulator based transmitter and 275fJ/bit at 8Gbps with BER

Silicon photonic links based on ring-resonator devices provide a unique opportunity to deliver distance-independent connectivity, whose pin-bandwidth scales with the degree of wavelength-division multiplexing. However, reliability and robustness are major challenges to widespread adoption of ring-based silicon photonics. In this work, a CMOS photonic transceiver architecture is demonstrated that incorporates the following enhancements: transmitters with independent dual-edge pre-emphasis to compensate for modulator bandwidth limitations; a bias-based tuning loop to calibrate for resonance wavelength variations; and an adaptive sensitivity-bandwidth receiver that can self-adapt for insitu variations in input capacitance, modulator/photodetector performance, and link budget.

Plotting lots of geographical data points usually clutters up a map. In this paper, we propose an approach to provide a summary view of geographical data by efficiently clustering. We present a novel data structure, called Geo-tree, which is extended from quad tree, and then develop two algorithms, which use Geo-tree to cluster geographic data and visualize the clusters with a heat map-like representation. The experimental results show that our approach is very efficient in a large scale, compared to K-means and HAC, and the clustering results are comparable to theirs.

We demonstrate the operation of an ultra-compact coherent receiver for linear optical phase demodulation. The receiver, based on a broadband optical phase-locked loop (OPLL) has a bandwidth of 1.5 GHz. Physical delay in the feedback path is dramatically reduced by incorporating novel photonic and electronic components. Using the receiver in an analog link experiment, a spurious free dynamic range of 122dBHz2/3 is measured at 300 MHz. Additionally, the link loss is −2dB at low frequencies.

We demonstrate a novel photonic integrated circuit(PIC) that combines an ultra compact trench beam splitter with monolithically integrated photodetectors and modulators. A coherent receiver is realized by flip chip bonding of this PIC with an electronic integrated circuit (EIC). Preliminary system results yield a third-order intermodulation distortion suppression of 46 dB at a signal frequency of 300 MHz.

An ultracompact buried heterostructure photonic crystal nanocavity laser exhibits a small energy cost of 8.76 fJ/bit with 20-Gbit/s modulation by optical pumping. The maximum output power in waveguide and the external differential quantum efficiency are −10.3 dBm and 53%, respectively.

With phase modulation, it is possible to realize high dynamic range analog optical links, provided the transmitted radio frequency (RF) signal can be linearly demodulated. The linearity of traditional interferometer-based phase demodulators, however, is often limited by their sinusoidal response. To achieve high linearity, negative feedback is introduced to suppress non-linearities arising from the phase demodulation process [1]. High feedback gain reduces the net phase swing across the demodulator such that it operates within the linear regime. Additionally, both the signal and the noise are reduced by the same feedback factor, so there is no penalty in signal-to-noise ratio (SNR) [1]. The challenge is to make a receiver incorporating feedback that is operable at high frequencies. Because high loop gain as well as a wide bandwidth is required for efficient phase tracking, the physical delay in the feedback path must be kept sufficiently short in order to prevent the loop from oscillating. Previously, we have demonstrated an ultra-compact grating-based beam splitter [2], which divides the incoming optical beams in a region, over 30 times shorter than a conventional surface-ridge Multimode Interference (MMI) beam splitter. This key feature leads to a significant reduction in loop delay.

We provide detailed experimental study of reflectivity, insertion loss, and interference extinction ratio for our recently proposed and demonstrated grating-based beam splitter. Both low- loss and high-extinction-ratio devices are demonstrated for reflectivities close to 50%.

A novel, InGaAsP/InP ultra-compact grating-based beam splitter that has less than 1.8 dB of loss has been fabricated. The beam splitter exhibits 50/50 splitting with a length of less than 25 mum for 1555 nm wavelength.

A 40 Gbps RZ all-optical buffering method, implemented by FBG and tunable wavelength converter, is presented. Preliminary results of time-delay up to 7 /spl mu/s and pulse broadening were measured. System measurements at 10 Gbps show the desired delay programmability.

The high spatial resolution, controlled etch profiles and uniformity of etching that is achievable with ion-assisted etch processes appear to be counterbalanced with ion-induced defects introduced into the material. We describe assessments of such damage introduced into InP, and propagated into material structures regrown onto those InP substrates. Particular etch chemistries, effective for patterning InP, may have capabilities of mitigating ion-generated defects.