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A QD laser with the dots-in-a-well structure (QDWELL laser) is characterized by the increased emission wavelength and low threshold current density. However, QDWELL laser manifests a high performance for the pulse repetition frequencies up to 7 GHz. The optical injection locking of semiconductor lasers substantially improves their performance. We, for the first time, investigated theoretically the...
In this paper, the impact of the evolution and successive compatibility requirements between different legacy technologies in optical access fibre is assessed. Various relevant factors will be summarized, as they have been elsewhere discussed, and the limitations stemming from each mapped. The considered stringing factors can be mainly grouped in: fibre inherent impairments, standards and technologic...
We consider the problems of both static and dynamic resource allocation in spectrum flexible (flexi-grid) optical networks. We present algorithms for planning such networks given the requested demand rates. We also present dynamic spectrum allocation policies to serve time-varying traffic and analyze their blocking performance for the dynamic operation of a flexi-grid network.
We demonstrate that the super-resolution imaging of a commercial Blu-ray® disk containing a one-dimensional array of 200 nm width stripes separated by 100 nm width grooves can be achieved using high-index microspheres in a liquid environment. By using barium titanate glass microspheres (2–20 μm diameters) with index around 1.9 totally immersed in isopropanol with index 1.37 we demonstrate better than...
One of the possible solutions is to use space division multiplexing in order to overcome the capacity crunch. Few mode fibers (FMF) have attracted a lot of attention in the recent years, however still a lot of research is required to enable transmission over FMF. One of the problems with the realization of FMF transmission is that these fibers have a modal dispersion which results in high number of...
Passive optical network (PON) architectures and systems of today are not efficient in utilizing capacity and spectrum. The daily usage patterns and the ever-growing bandwidth demand in access require a transport technology that is dynamically operated and that is based on wavelength division multiplexing (WDM). FlexPON is designed to meet those requirements: it combines a reconfigurable WDM layer...
Recent results on the development of active metallic nanocavities integrated with organic dye molecules in a J-aggregate state will be presented. Highly efficient SERS, the photoluminescence enhancement and photoluminescence lifetime modification have been observed at nanowire junctions.
The polarization-dependent gain process in Raman amplification based all-optical polarization control is investigated. We map the output signal degree of polarization and polarization-dependent in order to asses the signal pulling process over the entire Raman gain bandwidth. We show that, in the undepleted regime, the signal pulling process is more efficient for higher pump powers, whereas for the...
This paper examines the theoretical performance of five different pulse modulation schemes: Differential Pulse Position Modulation; Digital PIM, Dual Header PIM, Digital Pulse Position Modulation and Dicode Pulse Position Modulation. The optical channel considered is graded-index plastic optical fibre with a Gaussian shape impulse response. It is concluded that, on the basis of overall performance...
Numerical simulations have shown a significant influence of group-velocity dispersion (GVD) of the highly nonlinear fiber on the transfer characteristics of a nonlinear amplifying loop mirror (NALM). The effect is especially strong for the anomalous dispersion regime where an interaction of GVD and self-phase modulation (SPM) leads to formation of high-order solitons. The irregularities of the resulting...
Coherent communications have become a commercial reality with the deployment of 40 G and 100 G systems using Quadrature Phase Shift Keying (QPSK) in the core network. In the next evolution of these systems higher order modulation formats have the potential to significantly increase capacity while maintaining the baud rate at levels which allow the use of readily available lower cost electro-optics...
In this paper, we provide a performance comparison and analysis between a hybrid 1-D WDM/OCDMA system and a 2-D WHTS OCDMA system. In the hybrid system, OOC is employed as users code sequence of the OCDMA dimension. The simulation results show that the hybrid system presents better performance than the 2-D WHTS OCDMA system, and show also that under a standard BER scenario, i.e., BER = 10−9, the hybrid...
Physics and characteristics of a hybrid vertical-cavity laser that can be an on-chip Si light source with high speed and low energy consumption are discussed.
We proposed a new 60 GHz multiband-orthogonal frequency-division-multiplexing (MB-OFDM) radio-over-fiber (ROF) system using millimeter-wave (MMW) photonic techniques. A simple optical modulation scheme is developed to generate 60 GHz carrier by the sixth-harmonic term of local oscillator (LO) frequency. Moreover, the experimental setup of proposed system to demonstrate that the wireless MMW photonic...
The quenching of emission in proximity to metallic surfaces via non-radiative energy transfer is studied for sensing applications. It can also be used for the measurement of distances on the nanoscale. We report on energy transfer from a plane of CdTe quantum dots (QDs) plane to a plane of gold (Au) nanoparticles. Both photoluminescence (PL) and luminescence lifetime measurements demonstrate that...
We review the state-of the art of long-wavelength VCSELs. Furthermore, the short-cavity concept which has already been successfully implemented in 1.55 μm devices is extended to 1.3 μm devices resulting in excellent static and dynamic device properties. In particular, high output powers of 1.8 mW at an ambient temperature of 80 °C, high differential quantum efficiencies up to 56% and wall-plug efficiencies...
Plasmonic waveguides bear a lot of potential for photonic applications. However, one of the challenges for implementing them in devices is the low coupling efficiency to and from optical fibers. We report on our approach to facilitate the coupling efficiency with the use of metallic nanoantennas. The classical dipole antenna scheme can be improved by changing the nanoantenna geometry, adding constructive...
In this paper, the interaction of quantum emitters with plasmonic nanostructures and the resulting enhancement is studied. Special focus is placed on emitters with less than unity quantum efficiency, such as luminescent systems, and the effect the intrinsic losses have on fluorescence quenching in the extreme near field of metallic structures. With the example of a luminescent organic semiconductor...
High contrast gratings (HCG) have drained recently highly attractive perspectives for VCSEL devices through the wide potentialities for obtaining unique optical properties with these integrable optical elements [1], in contrast to conventional Bragg reflectors. Since most of the HCG approaches on III-V based photonic devices are based on semiconductor/air-gap structures, strong limitations are foreseen...
We propose a novel approach for in-band OSNR monitoring based on the Brillouin fiber ring laser seeded by the optical channel to be monitored. This technique is demonstrated experimentally and numerically for various bit rates and modulation formats and shows a reduction of the required input power into the monitor along with a large and tunable dynamic monitoring range.
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