348 research outputs found
Multi-level optical signal generation using a segmented-electrode InP IQ-MZM with integrated CMOS binary drivers
We present a segmented-electrode InP IQ-MZM, capable of multi-level optical signal generation (5-bit per I/Q arm) by employing direct digital drive from integrated, low-power (1W) CMOS binary drivers. Programmable, multi-level operation is demonstrated experimentally on one MZM of the device
Figure 1: Experimental setup 40 Gb/s NRZ Wavelength Conversion with Enhanced 2R Regeneration Characteristics using a Differentially-biased SOA-MZI switch
Abstract We present error-free 40 Gb/s NRZ signal wavelength conversion with a differential biasing scheme in a SOA -Mach Zehnder Interferometer. Experimental performance analysis shows 1.7 dB negative power penalty and enhanced 2R regenerative characteristics
Soliton switching using cascaded nonlinear-optical loop mirrors
We demonstrate multiple-peaked switching in a nonlinear-optical loop mirror and present an experimental investigation of device cascading in the soliton regime based on a sequence of two independent nonlinear-optical loop mirrors. Cascading leads to an enhanced switching response with sharper switching edges, flattened peaks, and increased interpeak extinction ratios. We observe that pulses emerging from the cascade retain the sech2 temporal profile of a soliton with minimal degradation in the spectral characteristics
O-band QKD link over a multiple ONT loaded carrier-grade GPON for FTTH applications
We have successfully integrated an O-band commercial Quantum-Key-Distribution
(QKD) system over a lit GPON testbed that replicates a carrier-grade
Fiber-to-the-Home (FTTH) optical access network with multiple ONTs to emulate
real-life FTTH operational deployments.Comment: 3 page
Packet clock recovery using a bismuth oxide fiber-based optical power limiter
Abstract: We demonstrate an optical clock recovery circuit that extracts the line rate component on a per packet basis from short data packets at 40 Gb/s. The circuit comprises a Fabry-Perot filter followed by a novel power limiting configuration, which in turn consists of a 5m highly nonlinear bismuth oxide fiber in cascade with an optical bandpass filter. Both experimental and simulation-based results are in close agreement and reveal that the proposed circuit acquires the timing information within only a small number of bits, yielding a packet clock for every respective data packet. Moreover, we investigate theoretically the scaling laws for the parameters of the circuit for operation beyond 40 Gb/s and present simulation results showing successful packet clock extraction for 160 Gb/s data packets. Finally, the circuit's potential for operation at 320 Gb/s is discussed, indicating that ultrafast packet clock recovery should be in principle feasible by exploiting the passive structure of the device and the fsec-scale nonlinear response of the optical fiber
Mutation screening of patients with Alzheimer disease identifies APP locus duplication in a Swedish patient
BACKGROUND: Missense mutations in three different genes encoding amyloid-Ī² precursor protein, presenilin 1 and presenilin 2 are recognized to cause familial early-onset Alzheimer disease. Also duplications of the amyloid precursor protein gene have been shown to cause the disease. At the Dept. of Geriatric Medicine, Karolinska University Hospital, Sweden, patients are referred for mutation screening for the identification of nucleotide variations and for determining copy-number of the APP locus.
METHODS: We combined the method of microsatellite marker genotyping with a quantitative real-time PCR analysis to detect duplications in patients with Alzheimer disease.
RESULTS: In 22 DNA samples from individuals diagnosed with clinical Alzheimer disease, we identified one patient carrying a duplication on chromosome 21 which included the APP locus. Further mapping of the chromosomal region by array-comparative genome hybridization showed that the duplication spanned a maximal region of 1.09 Mb.
CONCLUSIONS: This is the first report of an APP duplication in a Swedish Alzheimer patient and describes the use of quantitative real-time PCR as a tool for determining copy-number of the APP locus
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