1,782 research outputs found
Dispersion monitoring for high-speed WDM networks via two-photon absorption in a semiconductor microcavity
Due to the continued demand for bandwidth, network operators have to increase the data rates at which individual wavelengths operate at. As these data rates will exceed 100 Gbit/s in the next 5-10 years, it will be crucial to be able to monitor and compensate for the amount of chromatic dispersion encountered by individual wavelength channels. This paper will focus on the use of the novel nonlinear optical-to-electrical conversion process of two-photon absorption (TPA) for dispersion monitoring. By incorporating a specially designed semiconductor microcavity, the TPA response becomes wavelength dependent, thus allowing simultaneous channel selection and monitoring without the need for external wavelength filterin
Optical signal processing via two-photon absorption in a semiconductor microcavity for the next generation of high-speed optical communications network
Due to the introduction of new broadband services, individual line data rates are expected to exceed 100 Gb/s in the near future. To operate at these high speeds, new optical signal processing techniques will have to be developed. This paper will demonstrate that two-photon absorption in a specially designed semiconductor microcavity is an ideal candidate for optical signal processing applications such as autocorrelation, sampling, and demultiplexing in high-speed wavelength-division-multiplexed (WDM) and hybrid WDM/optical time-division-multiplexed networks
Nonlinear optical thresholding in a 4-Channel OCDMA system via two-photon absorption
We demonstrate the use of a Two-Photon Absorption based detector in an OCDMA system. This detector provides a significant performance improvement over standard linear detection
Principles of Neuromorphic Photonics
In an age overrun with information, the ability to process reams of data has
become crucial. The demand for data will continue to grow as smart gadgets
multiply and become increasingly integrated into our daily lives.
Next-generation industries in artificial intelligence services and
high-performance computing are so far supported by microelectronic platforms.
These data-intensive enterprises rely on continual improvements in hardware.
Their prospects are running up against a stark reality: conventional
one-size-fits-all solutions offered by digital electronics can no longer
satisfy this need, as Moore's law (exponential hardware scaling),
interconnection density, and the von Neumann architecture reach their limits.
With its superior speed and reconfigurability, analog photonics can provide
some relief to these problems; however, complex applications of analog
photonics have remained largely unexplored due to the absence of a robust
photonic integration industry. Recently, the landscape for
commercially-manufacturable photonic chips has been changing rapidly and now
promises to achieve economies of scale previously enjoyed solely by
microelectronics.
The scientific community has set out to build bridges between the domains of
photonic device physics and neural networks, giving rise to the field of
\emph{neuromorphic photonics}. This article reviews the recent progress in
integrated neuromorphic photonics. We provide an overview of neuromorphic
computing, discuss the associated technology (microelectronic and photonic)
platforms and compare their metric performance. We discuss photonic neural
network approaches and challenges for integrated neuromorphic photonic
processors while providing an in-depth description of photonic neurons and a
candidate interconnection architecture. We conclude with a future outlook of
neuro-inspired photonic processing.Comment: 28 pages, 19 figure
Coherent terabit communications with microresonator Kerr frequency combs
Optical frequency combs enable coherent data transmission on hundreds of
wavelength channels and have the potential to revolutionize terabit
communications. Generation of Kerr combs in nonlinear integrated microcavities
represents a particularly promising option enabling line spacings of tens of
GHz, compliant with wavelength-division multiplexing (WDM) grids. However, Kerr
combs may exhibit strong phase noise and multiplet spectral lines, and this has
made high-speed data transmission impossible up to now. Recent work has shown
that systematic adjustment of pump conditions enables low phase-noise Kerr
combs with singlet spectral lines. Here we demonstrate that Kerr combs are
suited for coherent data transmission with advanced modulation formats that
pose stringent requirements on the spectral purity of the optical source. In a
first experiment, we encode a data stream of 392 Gbit/s on subsequent lines of
a Kerr comb using quadrature phase shift keying (QPSK) and 16-state quadrature
amplitude modulation (16QAM). A second experiment shows feedback-stabilization
of a Kerr comb and transmission of a 1.44 Tbit/s data stream over a distance of
up to 300 km. The results demonstrate that Kerr combs can meet the highly
demanding requirements of multi-terabit/s coherent communications and thus
offer a solution towards chip-scale terabit/s transceivers
Simultaneous chromatic dispersion, polarization-mode-dispersion and OSNR monitoring at 40Gbit/s
A novel method for independent and simultaneous monitoring of chromatic dispersion ( CD), first-order PMD and OSNR in 40Gbit/s systems is proposed and demonstrated. This is performed using in-band tone monitoring of 5GHz, optically down-converted to a low intermediate-frequency (IF) of 10kHz. The measurement provides a large monitoring range with good accuracies for CD (4742 +/- 100ps/nm), differential group delay (DGD) (200 +/- 4ps) and OSNR (23 +/- 1dB), independently of the bit-rate. In addition, the use of electro-absorption modulators (EAM) for the simultaneous down-conversion of all channels and the use of low-speed detectors makes it cost effective for multi-channel operation. (C) 2008 Optical Society of Americ
Wavelength conversion for WDM communication systems using four-wavemixing in semiconductor optical amplifiers
Four-wave mixing (FWM) in semiconductor optical amplifiers is an attractive mechanism for wavelength conversion in wavelength-division multiplexed (WDM) systems since it provides modulation format and bit rate transparency over wide tuning ranges. A series of systems experiments evaluating several aspects of the performance of these devices at bit rates of 2.5 and 10 Gb/s are presented. Included are single-channel conversion over 18 nm of shift at 10 Gb/s, multichannel conversion, and cascaded conversions. In addition time resolved spectral analysis of wavelength conversion is presented
Simultaneous Compression of Multiple Pulse Streams for All-Optical Serial/Parallel Data Exchanges
We present our recent development of a simultaneous compression of multiple pulse streams utilizing the distributed Raman amplifier (DRA) for applications in serial/parallel high-speed data exchange. The optical clock pulse compression is operated based on adiabatic soliton compressor using DRA with pulsewidth tunable and multiple wavelength operations. We show an experimental demonstration of a simultaneous compression up to four 10 GHz clock pulse trains to picosecond pulsewidth range. The compressed multiple pulse streams are then used for applications in serial-to-parallel and parallel-to-serial data conversions which are one of key functionalities to realize all-optical wavelength/time-division trans-multiplexing in heterogeneous optical networks
Influence of Behavioral Models on Multiuser Channel Capacity
In order to characterize the channel capacity of a wavelength channel in a
wavelength-division multiplexed (WDM) system, statistical models are needed for
the transmitted signals on the other wavelengths. For example, one could assume
that the transmitters for all wavelengths are configured independently of each
other, that they use the same signal power, or that they use the same
modulation format. In this paper, it is shown that these so-called behavioral
models have a profound impact on the single-wavelength achievable information
rate. This is demonstrated by establishing, for the first time, upper and lower
bounds on the maximum achievable rate under various behavioral models, for a
rudimentary WDM channel model
- …