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Single photon detectors based on superconductor nanowires (SNSPDs) provide high efficiency and good timing performance, as well as broad optical detection bandwidth. To move towards applications in high bandwidth quantum communication and processing, ultrafast detectors with high efficiency are needed. We realize compact SNSPDs with sub-micrometer effective length by aligning the nanowire perpendicular...
Optical frequency combs (OFCs) are a revolutionary light source for numerous applications due to their precisely spaced coherent optical wavelengths. his paper will focus on OFCs for employment in next generation dense/ultra-dense wavelength division multiplexed high-speed optical communication systems, which places stringent requirements on the OFC. These requirements include stability, linewidth,...
Content Delivery Networks (CDNs) are a major enabler of large-scale content distribution for Internet applications. Many of these applications require high bandwidth and low latency for a satisfactory user experience, e.g., cloud gaming, augmented reality, tactile Internet and vehicular communications [1]. Replication is one of the most prominent solutions to meet the requirements of latency-sensitive...
In a Cloud Radio Access Network (C-RAN) architecture, different baseband processing functions (BPFs) splits options are available on the interface between the central unit (CU) and the radio units (RUs) [1]. A lower layer split, e.g., low-physical (PHY), can support advanced radio coordination techniques, for example Joint Reception (JR) Coordinated MultiPoint (JR-CoMP) [2]. However, the interface...
Protein detection by optical measurement can be obtained through absorption measurements using wavelengths in the range between 270 and 280 nm. Efficient light sources or optical filters in this wavelength range can avoid the use of spectral measurement for detection [1]. A study about the relationship between the reflectivity in the near UV and the vertical aspect ratio was performed for gratings...
Extreme events and rogue waves are ubiquitous in complex systems [1] and a lot of efforts are nowadays focused in developing reliable analysis techniques for their detection and prediction [2]. Laser systems displaying extreme pulses in their output intensity are ideal candidates for performing laboratory controlled experiments that allow testing novel diagnostic tools to detect warning signals of...
Data Centers (DC) are continuously expanding in size as data migrate to the cloud leading to an unparalleled growth of the traffic circulating in the DC network and reaching several Petabytes/s across the various levels in the fat tree architecture. Currently, handling and forwarding of the traffic is accommodated by electronic switches at each hop that consume several tens of pJ/bit taking into account...
Periodically patterning Si with a pitch small enough to suppress diffraction, we synthesize an effective photonic medium with refractive index between those of Si and the cladding material. This technique releases new degrees of freedom in engineering of light-matter interaction, chromatic dispersion and light propagation in Si photonic waveguides. We report our advances in the development of subwavelength...
Far-field super-resolution (SR) microscopy has developed to be an important tool in life sciences. However, it relies on, and therefore is limited by the ability to control the fluorescence of label molecules or nanoparticles. While in many cases, label-free far-field microscopy is required, an equivalent SR technique is not available.
Creating isolated, two-level quantum systems (qubits) that can be coupled to perform gate operations or study many-body quantum systems is one of the outstanding goals in quantum information science. In cold-atom systems, Rydberg states have been used to create and coherently control non-classical states of light and atoms. Is there a way of combining the proven successes in cold-atom systems with...
An elongated bottle microresonator with parabolic nanoscale effective radius variation possesses series of dense and equally spaced optical eigenfrequencies. The separation of these frequencies can match the eigenfrequency of its axially symmetric acoustic mode. At very low temperatures corresponding to very high mechanical Q-factor of the resonator and low noise, the axial series of both optical...
In many different AlGaAs-based photonic and optical devices, the selective oxidation of an Al-rich layer is a very efficient way to create a lateral electrical and optical confinement. The degree of lateral confinement can thus be adjusted with the depth of the oxide within the structure. It is then of primary importance to control the lateral spreading of the oxidation reaction and that in all the...
High-performance server boards rely on multi-socket architectures for increasing the processing power density on the board level and for flattening the data center networks beyond leaf-spine architectures. Scaling, however, the number of processors per board and retaining at the same time low-latency and high-throughput metrics puts current electronic technologies into challenge. In this article,...
While disorder has been mostly regarded as a negative factor in technology its underlying scientific aspects have intrigued researchers. Disorder is intrinsic with random lasers and light diffusers, examples of active and passive photonic systems. Progress in controlling its amount, nature and distribution and how light interacts and is affected by it can permit designing better devices and take advantage...
Plasmons - collective oscillations of electrons in conducting materials - have provided the tools to engineer artificial structures capable of manipulating light over wide spectral and spatial ranges. The emergence of exfoliated 2D materials as excellent plasmonic systems has open new possibilities to explore optical phenomena at atomic scales and their applications in light modulation, sensing, and...
Mode division multiplexed (MDM) transmission is prone to mix, and necessitates that all spatial channels on a carrier wavelength remain intact, so that the information set can be unraveled at the receiver following multi-channel coherent detection and digital signal processing. This requirement is extended to the network switching gear, which should ‘jointly switch’ all modes. Wavelength-selective...
Adaptive optical multi-input multi-output (MIMO) signal processing is employed to compensate for intermodal coupling in short-reach direct-detection mode-division multiplexing systems. Complexity is minimized by cascading two stages of fundamentally lossless devices. All modes are first separated by a fixed demultiplexer, such as a mode-selective photonic lantern or multi-plane converter. Coupling...
The coherent optical systems based on polarization multiplexing deployed in core networks in the last years have generated a renewed interest for the study of polarization effects in fiber optic links [1]. Fluctuations of the state of polarization (SOP) of the optical signal, combined with polarization-dependent loss (PDL) and polarization mode dispersion (PMD), can affect the performance of coherent...
The tremendous traffic growth in intra/inter-datacenters requires low-cost high-speed integrated solutions [1]. To enable a significantly reduced footprint directly modulated lasers (DMLs) have been proposed instead of large external modulators. However, it is challenging to use DMLs due to their low dispersion tolerance and limited achievable extinction ratio (ER). A promising solution to this problem...
Silicon and germanium are transparent up to approximately 8 µm and 15 µm, respectively, thus offering a range of applications in biochemical and environmental sensing, medicine, astronomy and communications. In this paper we present our recent results on germanium and silicon modulators and detectors suitable for mid-infrared communications.
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