7,640 research outputs found
The Orbital Angular Momentum of Light for Ultra-High Capacity Data Centers
The potential of orbital angular momentum (OAM) of light in data center scenarios is presented. OAMs can be exploited for short reach ultra-high bit rate fiber links and as additional multiplexing domain in transparent ultra-high capacity optical switches. Recent advances on OAM integrated photonic technology are also reported. Finally demonstration of OAM-based fiber links (aggregate throughput 17.9 Tb/s) and two layers OAM-WDM-based optical switches are presented exploiting OAM integrated components and demonstrating the achievable benefits in terms of size, weight and power consumption (SWaP) compared to different technologies
Plasmonic nanoantennas as integrated coherent perfect absorbers on SOI waveguides for modulators and all-optical switches
The performance of plasmonic nanoantenna structures on top of SOI wire
waveguides as coherent perfect absorbers for modulators and all-optical
switches is explored. The absorption, scattering, reflection and transmission
spectra of gold and aluminum nanoantenna-loaded waveguides were calculated by
means of 3D finite-difference time-domain simulations for single waves
propagating along the waveguide, as well as for standing wave scenarios
composed from two counterpropagating waves. The investigated configurations
showed losses of roughly 1% and extinction ratios greater than 25 dB for
modulator and switching applications, as well as plasmon effects such as strong
field enhancement and localization in the nanoantenna region. The proposed
plasmonic coherent perfect absorbers can be utilized for ultracompact
all-optical switches in coherent networks as well as modulators and can find
applications in sensing or in increasing nonlinear effects.Comment: 10 pages, 6 figure
Ultracompact and low-power optical switch based on silicon photonic crystals
Switching light is one of the most fundamental functions of an optical circuit. As such, optical switches are a major research topic in photonics, and many types of switches have been realized. Most optical switches operate by imposing a phase shift between two sections of the device to direct light from one port to another, or to switch it on and off, the major constraint being that typical refractive index changes are very small. Conventional solutions address this issue by making long devices, thus increasing the footprint, or by using resonant enhancement, thus reducing the bandwidth. We present a slow-light-enhanced optical switch that is 36 times shorter than a conventional device for the same refractive index change and has a switching length of 5.2âm.The work was funded through the EU FP6-FET
âSplashâ project and we acknowledge the Nanostructuring
Platform of EU FP6-NoE âepixnetâ for technical
support. T. P. White is supported by an 1851
Royal Commission Research Fellowship
Optical Multicast Routing Under Light Splitter Constraints
During the past few years, we have observed the emergence of new applications
that use multicast transmission. For a multicast routing algorithm to be
applicable in optical networks, it must route data only to group members,
optimize and maintain loop-free routes, and concentrate the routes on a subset
of network links. For an all-optical switch to play the role of a branching
router, it must be equipped with a light splitter. Light splitters are
expensive equipments and therefore it will be very expensive to implement
splitters on all optical switches. Optical light splitters are only implemented
on some optical switches. That limited availability of light splitters raises a
new problem when we want to implement multicast protocols in optical network
(because usual multicast protocols make the assumption that all nodes have
branching capabilities). Another issue is the knowledge of the locations of
light splitters in the optical network. Nodes in the network should be able to
identify the locations of light splitters scattered in the optical network so
it can construct multicast trees. These problems must be resolved by
implementing a multicast routing protocol that must take into consideration
that not all nodes can be branching node. As a result, a new signaling process
must be implemented so that light paths can be created, spanning from source to
the group members
Mixed regime of light-matter interaction revealed by phase sensitive measurements of the dynamical Franz-Keldysh effect
The speed of ultra-fast optical switches is generally limited by the
intrinsic electronic response time of the material. Here we show that the phase
content of selected electromagnetic pulses can be used to measure the
timescales characteristic for the different regimes of matter-light
interactions. By means of combined single cycle THz pumps and broadband optical
probes, we explore the field-induced opacity in GaAs (the Franz-Keldysh
effect). Our phase-resolved measurements allow to identify a novel quasi-static
regime of saturation where memory effects are of relevance
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