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We demonstrate a novel on-board chip-to-chip optical interconnect using long-range surface plasmon polariton (LR-SPP) waveguides that feature 2.5-cm-long gold strips embedded in a low loss polymer cladding. A TM-mode vertical-cavity surface-emitting laser (VCSEL) operating at a wavelength of 1.3 microm was butt-coupled into the waveguides in order to excite a fundamental LR-SPP mode and then the transmitted light was received with a photo-diode (PD). The waveguide width is varied in the range of 1.5-5.0 microm in order to optimize the insertion loss where the 3-microm-wide waveguide provides a minimum insertion loss of -17 dB, consisting of 6 dB/cm propagation loss and 2 dB coupling loss. An interconnect system based on the optimized waveguide with a 4-channel array is assembled with the arrayed optoelectronic chips. It shows the feasibility of 10 Gbps (2.5 Gbps x 4 channels) signal transmission indicating that the LR-SPP waveguide is a potential transmission line for optical interconnection.

This paper aims to present the design and the achieved results on a CMOS electronic and photonic integrated device for low cost, low power, transparent, mass-manufacturable optical switching. An unprecedented number of integrated photonic components (more than 1000), each individually electronically controlled, allows for the realization of a transponder aggregator device which interconnects up to eight transponders to a four direction colorless-directionless-contentionless ROADM. Each direction supports 12 200-GHz spaced wavelengths, which can be independently added or dropped from the network. An electronic ASIC, 3-D integrated on top of the photonic chip, controls the switch fabrics to allow a complete and microsecond fast reconfigurability

Reversible formate (HCOO–) dehydrogenation and bicarbonate (HCO3 –) hydrogenation would be desirable for the utilization and storage of hydrogen (H2) as an effective energy carrier. Carbon-supported Pd-based nanoparticles demonstrated enormous competitive advantages for these reactions. However, the fundamental mechanisms underlying these reversible reactions have not yet been elucidated. Herein, we report the reaction pathways for reversible reactions on a Pd-based catalyst using density functional theory (DFT) calculations and propose key factors for improving the reaction efficiency. As the first essential step, the difficulty in the conventional DFT modeling, that is simulation of an anion environment caused by HCOO–, was overcome by designing two-sided Pd12 nanoclusters supported on graphene (Pd12NC-G) with extra electrons. Using Pd12NC-G, we demonstrated that the key factor determining the potential limiting steps for the reversible reaction was desorption of hydrogen in HCOO– dehydrogenation (1.24 eV) and HCO3 – hydrogenation (1.49 eV). The key factor was the same in Pd12NC-N1G, Pd12NC-N2G, and Pd12NC-N3G (where N1, N2, and N3 represent the number of N atoms doped on carbon). Among these, the Pd12NC-N2G model with the appropriate amount of nitrogen doping showed optimal hydrogen adsorption strength corresponding to the smallest d-band center and spin density values, resulting in the lowest energy barriers for HCOO– dehydrogenation (0.76 eV) and HCO3 – hydrogenation (0.96 eV). Based on harmonization between electronic and geometrical properties, we demonstrated that the appropriate level of nitrogen doping can provide the optimal balance between the magnitude of reactivity and the number of sites for improving the efficiency of the reversible reactions.