Accurate in situ measurement of peak noise and delay change inducedby interconnect coupling

An accurate in situ noise and delay measurement technique that considers interconnect coupling effects is presented. This paper improves upon previous work by proposing (1) a novel accurate peak detector to measure on-chip crosstalk noise, and (2) in situ measurement structure to characterize the dynamic delay effect. A test chip was fabricated using 0.35-μm process and measured results demonstrate the effectiveness of the proposed technique. Noise peak measurements show 40-60 mV (1.8% average) accuracy to simulation results and dynamic delay change curve match well with SPICE. The proposed measurement technique can be used for interconnect model verification and calibration, and has applications to various design automation tools such as noise-aware static timing analysis     

NRZ operation at 40 Gb/s of a compact module containing an MQW electroabsorption modulator integrated with a DFB laser

NRZ operation at 40 Gb/s has been successfully performed using a very compact module of a multiple-quantum-well (MQW) electroabsorption modulator integrated with a distributed-feedback (DFB) laser. While the DFB laser is injected with a constant current, the integrated MQW electroabsorption modulator is driven with a 10-Gb/s electrical NRZ signal. A clearly opened eye diagram has been observed in the modulated light from the modulator. And a receiver sensitivity of -27.2 dBm at 10/sup -9/ has been experimentally confirmed in the bit-error-rate (BER) performance.     

Ortho-deuterium Raman laser using the S0(2) rotationaltransition in the mid-infrared region

Based on a calculation for the Raman gain coefficient of the S₀(2) transition in ortho-D₂, we have demonstrated the generation of first Stokes waves in the 15-16-μm spectral region. Use of ortho-D enriched by a catalytic converter enabled us to realize efficient conversion at room temperature. Stokes energies as high as 400 mJ were obtained     

7W operation of 644 nm wavelength laser diode arrays with index-guided structure

A 7 W operation of a red semiconductor array laser is achieved at a wavelength of 644 nm with high reliability for the first time. The uniform near-field pattern has been obtained by applying index-guided structure to the broad-stripe laser.     

Temperature influence on performance degradation of hydrogenated amorphous silicon solar cells irradiated with protons

This paper reports temperature influence on radiation degradation of hydrogenated amorphous silicon (a‐Si : H) solar cells. Degradation behaviors of a‐Si : H solar cells irradiated with protons at 331 K are compared with that at 298 K (room temperature). Variations with time in the post‐irradiation electrical properties are also investigated. It is found that the radiation degradation of the electrical properties at 331 K is significantly smaller than that at room temperature. Also, all the electrical properties (short‐circuit current, open‐circuit voltage, output maximum, and fill factor) recover with time after irradiation even at room temperature. The characteristic time of thermal annealing of short‐circuit current is larger as the temperature is higher. These results indicate that temperature during irradiation and elapsed time from irradiation to measurement is an important parameter for radiation degradation of a‐Si : H solar cells. Therefore, these parameters should be controlled in conducting the ground radiation tests. Copyright © 2012 John Wiley & Sons, Ltd.     

Interaction of Fragrance Materials With 2-Hydroxypropyl-beta-Cyclodextrin by Static and Dynamic Head-space Methods

The stability constants for the inclusion of fragrance materials with 2-hydroxypropyl-beta-cyclodextrin (2HP-beta-C yD) in aqueous solution have been determined by the static head-space method. The 1:1 stability constants obtained by this method were in reasonable agreement with the corresponding values in the literature. In addition, the release profiles of fragrance materials from 2HP-beta-CyD aqueous solution were investigated using the dynamic head-space method. It was found that the suppression of the fragrance materials release was dependent on their stability constants.     

Analysis of TE and TM modes in DFB lasers by two-dimensional theory

The two-dimensional theory of a distributed feedback (DFB) laser (which was previously presented and applied to the analysis of the laser threshold conditions for the transverse-electric (TE) mode in a simple three-layer waveguide structure) is developed to treat both TE and transverse-magnetic (TM) modes in a four-layer waveguide structure with a thin grating layer, which more closely reflects actual DFB laser structure. The differences between TE and TM modes for the dispersion relations and the laser threshold conditions are clarified. The effects of the waveguide structure (including grating layer thickness, refractive indexes of layers, coupling constant, and corrugation period) on the threshold gains and the gain differences between the two longitudinal modes on both sides of the Bragg frequencies are studied in detail for both TE and TM modes     

High-performance organic field-effect transistors with binary ionic liquids

High-performance rubrene single-crystal field-effect transistors are developed with binary ionic liquid electrolytes used for gating. Inclusion of small amount of inorganic salts in the ionic liquids enhances the degree of dissociation for the organic ions and accelerates formation of the electric-double-layers in response to the gate voltage. High carrier mobility of 2.9 cm²/Vs is achieved in the rubrene single-crystal transistors with the mixture ionic liquid. In addition to the advantage of the low-voltage operation due to concentrated field in ultra-thin electric-double-layers, drastically increased capacitance at above 100 Hz makes the technique of the ionic liquid gating more attractive for fast-switching devices.     

Organic field-effect transistors based on J-aggregate thin films of a bisazomethine dye

We report on the fabrication and the characterization of p-type organic field-effect transistors based on vapor-deposited J-aggregate bisazomethine dye thin films. The absorption spectra of this non-ionic organic semiconductor in the solid state show a strong influence of the film thickness on the J-aggregate formation. However, the electrical characteristics of the devices demonstrate that the hole transport properties do not vary significantly in films thicker than 100 nm. This is due to the fact that the J-aggregates are formed in this material at the surface of the crystalline grains and do not influence the semiconductor/gate dielectric interface and the charge transport properties of the devices. Hole field-effect mobilities as high as 2.4 × 10^?4 cm² V^?1 s^?1 were obtained and could be slightly improved by a solvent vapor treatment due to changes in the film crystallinity. Overall, this study demonstrates that J-aggregate bisazomethine dye thin films are good candidates for the realization of organic electronic devices.     

A 5-GByte/s data-transfer scheme with bit-to-bit skew control forsynchronous DRAM

This paper describes a 5-GByte/s data-transfer scheme suitable for synchronous DRAM memory. To achieve a higher data-transfer frequency, the properties were improved based on the frequency analysis of the memory system. Then, a bit-to-bit skew compensation technique that eliminates incongruent skew between the signals is described with a new, multioutput controlled delay circuit to accomplish bit-to-bit skew compensation by controlling transmission timing of every data bit. Simulated maximum data-transfer rate of the proposed memory system resulted in 5.1/5.8 GByte/s (321/365 MHz, ×64 bit, double data rate) for data write/read operation, respectively