Compact samples of nano-helices built by means of a focused ion beam technology with large bandwidth and high dichroism for circular polarization are promising for the construction of built-in-chip sensors, where the ideal transducer must be sufficiently confined without compromising its filtering ability. Direct all-optical measurements revealed the sample’s dichroic character with insufficient details because of scattering and diffraction interference. On the other hand, photoacoustic measurements resulted to be a possible alternative investigation, since they directly deal with absorbed power and allow to get clear evidences of the differential selection for the two opposite polarization states. Multi-level numerical simulations confirmed the experimental results, proving once again the reliability of photoacoustic technique and the versatility of this class of dichroic artificial materials.

Optical technology applied to on-chip wireless communication is particularly promising to overcome the performance limitations of the state-of-the-art networks on-chip. A key enabling component for such applications is the plasmonic antenna coupled to conventional silicon waveguides, which can guarantee full compatibility with standard optical circuitry. In this paper, we propose an antenna array configuration based on tilted plasmonic Vivaldi antennas coupled to a silicon waveguide. The details of the single antenna and of the array design are reported. The radiation characteristics of the array are suitable for on-chip point-to-point communication, i.e. in-plane maximum gain of 14.70 dB for an array with five antennas. The array exploits a travelling wave feeding scheme and, therefore, is compact in size (about 3.5 µm × 8.7 µm ).

Optical wireless networks-on-chip (OWiNoC) are considered as a possible solution to overcome the communication bottleneck due to wired interconnects in modern chip multi-processor systems. The efficient implementation of optical wireless links requires considering many different aspects, including analysis and deep understanding of the effects on the propagation of the electromagnetic field induced by the discontinuities that can be found in a realistic scenario. This letter aims at showing the impact determined by some of these discontinuities on optical links designed in Silicon-on-Insulator technology, exploiting simple point-to-point interconnections as a first example. Measurements and simulations confirm that multi.path phenomena, triggered by the multi-layer structure housing the antennas and the propagation paths, can have a serious impact on the link budget, with fading effects that may compromise the performance of the link. However, in the presented experimental results, thanks to a careful choice of the chip layer structure, received powers higher than those which could have been measured for optical links fabricated in an infinite homogeneous medium are observed, thus resulting beneficial for the connection’s power budget.

Networks-on-chip are being regarded as a promising solution to meet the on-going requirement for higher and higher computation capacity. In view of future kilo-cores architectures, electrical wired connections are likely to become inefficient and alternative technologies are being widely investigated. Wireless communications on chip may be therefore leveraged to overcome the bottleneck of physical interconnections. This work deals with wireless networks-on-chip at optical frequencies, which can simplify the network layout and reduce the communication latency, easing the antenna on-chip integration process at the same time. On the other end, optical wireless communication on-chip can be limited by the heavy propagation losses and the possible cross-link interference. Assessment of the optical wireless network in terms of bit error probability and maximum communication range is here investigated through a multi-level approach. Manifold aspects, concurring to the final system performance, are simultaneously taken into account, like the antenna radiation properties, the data-rate of the core-to core communication, the geometrical and electromagnetic layout of the chip and the noise and interference level. Simulations results suggest that communication up to some hundreds of μm can be pursued provided that the antenna design and/or the target data-rate are carefully tailored to the actual layout of the chip.

A structure featuring vertical directional coupling of long-range surface plasmon polaritons between strip waveguides at λ = 1.55 μm is investigated with the aim of producing efficient elements that enable optical multilayer routing for 3D photonics. We have introduced a practical computational method to calculate the interaction on the bent part. This method allows us both to assess the importance of the interaction in the bent part and to control it by a suitable choice of the fabrication parameters that helps also to restrain effects due to fabrication issues. The scheme adopted here allows to reduce the insertion losses compared with other planar and multilayer devices.

In this work, we analyze the effects of the presence of waveguides in a wireless on-chip optical channel, which act as obstacles for the rays composing the propagating signal. The analysis has been performed numerically by using the FDTD method, and the simulation results have been validated by the experimental characterization. This work focuses on the relationship between the received signal and the position of the obstacles on the circuit plane in a multilayered channel made of heterogeneous dielectric cladding. We show how the crossing waveguide perturbates the received power and we provide ad hoc guidelines for the best topological choices allowing to mitigate losses. Moreover, with a good agreement between numerical and experimental results, amounting to a variation of less than 1 dB, we have demonstrated that the effects of this perturbation in real chips can be predicted. The results of this analysis, as well as increasing the level of knowledge of on-chip optical wireless links, allow a better comprehension and control of unbound optical signals within the optical chip environment.