Multiwavelength NRZ-to-RZ conversion with significant timing-jitter suppression and SNR improvement

We demonstrate a novel, polarization-insensitive scheme for multiwavelength nonreturn-to-zero to return-to-zero format conversion at 10 Gb/s rate with significant timing-jitter suppression and signal-to-noise ratio improvement. The scheme utilizes a self-starting electroabsorption-modulator based optoelectronic oscillator that simultaneously generates a 10 GHz-rate microwave signal and a train of 15 ps-wide optical pulses with 40 fs timing jitter (100–10 MHz range). Under direct optical injection locking of the oscillator with an incoming data stream, we demonstrate the extraction of a high-quality clock that enables in-line format conversion of multiple, synchronized nonreturn-to-zero channels.     

Substrate specificity analysis of protein kinase complex Dbf2-Mob1 by peptide library and proteome array screening

Background  

The mitotic exit network (MEN) is a group of proteins that form a signaling cascade that is essential for cells to exit mitosis in Saccharomyces cerevisiae. The MEN has also been implicated in playing a role in cytokinesis. Two components of this signaling pathway are the protein kinase Dbf2 and its binding partner essential for its kinase activity, Mob1. The components of MEN that act upstream of Dbf2-Mob1 have been characterized, but physiological substrates for Dbf2-Mob1 have yet to be identified.     

10-GHz dispersion-managed soliton fiber-optical parametric oscillator using regenerative mode locking

We demonstrate a regeneratively mode-locked fiber-optical parametric oscillator that utilizes intracavity dispersion compensation to generate pulses at a 10-GHz repetition rate in both soliton and nonsoliton regimes. At the threshold pump power the generated pulses are close to fundamental solitons. At higher pump powers we found a significant deviation of the pulses from the sech2 shape. In addition, the use of an ultralow-jitter self-starting pump-pulse source in a regenerative feedback loop allows for a significant reduction of the signal's timing jitter and amplitude noise.     

Effect of swift heavy ion irradiation on ethylene–chlorotrifluoroethylene copolymer

The swift heavy irradiation induced changes taking place in ethylene–chlorotrifluoroethylene (E–CTFE) copolymer films were investigated in correlation with the applied doses. Samples were irradiated in vacuum at room temperature by lithium (50 MeV), carbon (85 MeV), nickel (120 MeV) and silver (120 MeV) ions with the fluence in the range of 1×10¹¹–3×10¹² ions cm^?2. Structural and thermal properties of the irradiated as well as pristine E–CTFE films were studied using FTIR, UV–visible, TGA, DSC and XRD techniques. Swift heavy ion irradiation was found to induce changes in E–CTFE depending upon the applied doses.     

Multivariate analysis for forensic characterization,discrimination, and classification of marker pen inks

The multivariate analysis methods have recently gained high popularity within the field of forensic sciences because of their high accuracy and precision. The accurate and unbiased results are the preliminary need for a forensic investigation. The aim of the present work is to examine the marker pen inks which are widely used in various places like documentation in parcels, for photograph attestation, and also as a study material in the classroom. This research is focused on the three important aspects; first is to characterize the marker inks, second, to discriminate permanent marker and whiteboard marker inks using destructive (extracting of ink samples from paper substrate) and nondestructive (without ink extraction) techniques of ultraviolet–visible absorbance combined with peak identification examination as well as chemometric methods, and the third is to build a classification model for permanent and whiteboard marker inks. It is concluded that the chemometric method, that is, principal component analysis provides better discrimination power as compared to visual examination. However, destructive and nondestructive approaches give almost similar discriminating power. The classification model developed using linear discriminant analysis provides 87.5% of correct classification of marker ink samples. The method can further be used to formulate a statistical model for the determination of class/group of the other forensic exhibits.     

Noise-figure limit of fiber-optical parametric amplifiers and wavelength converters: experimental investigation

Recent theoretical work predicts that the quantum-limited noise figure of a x(3)-based fiber-optical parametric amplifier operating as a phase-insensitive in-line amplifier or as a wavelength converter exceeds the standard 3-dB limit at high gain. The degradation of the noise figure is caused by the excess noise added by the unavoidable Raman gain and loss occurring at the signal and the converted wavelengths. We present detailed experimental evidence in support of this theory through measurements of the gain and noise-figure spectra for phase-insensitive parametric amplification and wavelength conversion in a continuous-wave amplifier made from 4.4 km of dispersion-shifted fiber. The theory is also extended to include the effect of distributed linear loss on the noise figure of such a long-length parametric amplifier and wavelength converter.