The integration of optical interconnections on ceramic substrates

High heat conductivity and high heat capacity make ceramic substrates indispensable to the manufacture of Multi-Chip Modules (MCM) and power electronics. In this paper a detailed description of the integration process of optical lines on to ceramic substrates is presented. The manufacturing of microgrooves in ceramic substrates and the process of integration of optical fibres and active elements is described. Coupling active elements to optical fibre is also presented. Through such an integrated optical line a 4 Gbps signal was transmitted. © 2016 Elsevier B.V. All rights reserved

Optical interconnections in future VLSI systems

This paper is focused on the latency and power dissipation in clock systems, which should be lower when the optical interconnects are applied. Simulation shows that the power consumed by an optical system is lower than that consumed by an electrical one, however the advantages of optics drastically decrease with the number of output nodes in H-tree. Additionally, simple replacement of an electrical system by an optical clock distribution network (CDN) results in high clock skew, which will be higher than 10% of the clock period for the 32 nm technology node

Realization of optical fibers terminated with ball lenses

In this article the process of realization of ball-lensed optical fibers is described. The implementation of four different types of ball-lensed optical fibers developed in Optical Fibers Techniques Laboratory at Lodz University of Technology is presented. Focal lengths of the presented microlenses, which were obtained in simulations and measurements, are also shown in this paper

Realization of optical fibers terminated with ball lenses

In this article the process of realization of ball-lensed optical fibers is described. The implementation of four different types of ball-lensed optical fibers developed in Optical Fibers Techniques Laboratory at Lodz University of Technology is presented. Focal lengths of the presented microlenses, which were obtained in simulations and measurements, are also shown in this paper

Ecological observations based on functional gene sequencing are sensitive to the amplicon processing method

Until recently, the de facto method for short-read-based amplicon reconstruction was a sequence similarity threshold approach (operational taxonomic units [OTUs]). This has changed with the amplicon sequence variant (ASV) method where distributions are fitted to abundance profiles of individual genes using a noise-error model. While OTU-based approaches are still useful for 16S rRNA/18S rRNA genes, where thresholds of 97% to 99% are used, their use for functional genes is still debatable as there is no consensus on clustering thresholds. Here, we compare OTU- and ASV-based reconstruction approaches and taxonomy assignment methods, the naive Bayesian classifier (NBC) and Bayesian lowest common ancestor (BLCA) algorithm, using a functional gene data set from the microbial nitrogen-cycling community in the Brouage mudflat (France). A range of OTU similarity thresholds and ASVs were used to compare amoA (ammonia-oxidizing archaea [AOA] and ammonia-oxidizing bacteria [AOB]), nxrB, nirS, nirK, and nrfA communities between differing sedimentary structures. Significant effects of the sedimentary structure on weighted UniFrac (WUniFrac) distances were observed for AOA amoA when using ASVs, an OTU at a threshold of 97% sequence identity (OTU-97%), and OTU-85%; AOB amoA when using OTU-85%; and nirS when using ASV, OTU-90%, and OTU-85%. For AOB amoA, significant effects of the sedimentary structures on UniFrac distances were observed when using OTU-97% but not ASVs, and the inverse was found for nrfA. Interestingly, conclusions drawn for nirK and nxrB were consistent between amplicon reconstruction methods. We also show that when the sequences in the reference database are related to the environment in question, the BLCA algorithm leads to more phylogenetically relevant classifications. However, when the reference database contains sequences more dissimilar to the ones retrieved, the NBC obtains more information

Towards reconfigurable optical networks on chip

The evolution of integrated circuit technology is causing system designs to move towards communication-based architectures. However, metallic interconnect networks (networks-on-chip) can be very costly in terms of power and silicon area and can thus become a bottleneck in system on chip design. Integrated optical networks-on-chip could be good candidates to overcome predicted interconnect limitations, as identified by the ITRS roadmap. This paper firstly presents a review of some potential data transport applications of integrated optical interconnect, as well as the necessary technology and passive devices. The second part of the paper concentrates on the optical network on chip concept, from system-level modelling aspects to first measured results of the passive network device