arXiv subjects

Wolfgang Freude

Publications and source records attributed to Wolfgang Freude.

39 records · Page 3Linked to original sources

arXiv2012

Adaptive Wavelet Collocation Method for Simulation of Time Dependent Maxwell's Equations

This paper investigates an adaptive wavelet collocation time domain method for the numerical solution of Maxwell's equations. In this method a computational grid is dynamically adapted at each time step by using the wavelet decomposition of the field at that time instant. In the regions where the fields are highly localized, the method assigns more grid points; and in the regions where the fields are sparse, there will be less grid points. On the adapted grid, update schemes with high spatial order and explicit time stepping are formulated. The method has high compression rate, which substantially reduces the computational cost allowing efficient use of computational resources. This adaptive wavelet collocation method is especially suitable for simulation of guided-wave optical devices.

math.NA↗

arXiv2011

Photonic Wire Bonds for Terabit/s Chip-to-Chip Interconnects

Photonic integration has witnessed tremendous progress over the last years, and chip-scale transceiver systems with Terabit/s data rates have come into reach. However, as on-chip integration density increases, efficient off-chip interfaces are becoming more and more crucial. A technological breakthrough is considered indispensable to cope with the challenges arising from large-scale photonic integration, and this particularly applies to short-distance optical interconnects. In this letter we introduce the concept of photonic wire bonding, where transparent waveguide wire bonds are used to bridge the gap between nanophotonic circuits located on different chips. We demonstrate for the first time the fabrication of three-dimensional freeform photonic wire bonds (PWB), and we confirm their viability in a multi-Terabit/s data transmission experiment. First-generation prototypes allow for efficient broadband coupling with overall losses of only 1.6 dB. Photonic wire bonding will enable flexible optical multi-chip assemblies, thereby challenging the current paradigm of highly-complex monolithic integration.

physics.optics↗

arXiv2011

Comment to "Nonreciprocal Light Propagation in a Silicon Photonic Circuit"

In the article "Nonreciprocal Light Propagation in a Silicon Photonic Circuit" (Science 333, 729-733 (2011) a nonreciprocal waveguide system based on a combination of silicon, dielectrics and metals is reported. In this Comment it is explained that the interpretation with respect to nonreciprocity in this paper is incorrect and conflicts with the fundamental Lorentz reciprocity theorem. It is further pointed out that a previous publication already introduced the device concept.

physics.optics↗