Design Considerations for a Transparent Mode Group Diversity Multiplexing Link

Mode group diversity multiplexing (MGDM) is an optical multiple-input-multiple-output technique that aims at creating independent communication channels over a multimode fiber, using subsets of propagating modes. This letter deals with the analysis of an MGDM point-to-point link, transparent to the transmission format. The geometry of a mode-group selective multi/demultiplexer is optimized in order to minimize the crosstalk among the channels. The power penalty is calculated when a zero-forcing algorithm is used to mitigate the crosstalk     

Mitigation of Impairments in MGDM Transmission With Mode-Selective Spatial Filtering

A model for a mode group diversity multiplexing (MGDM) transmission system is derived. The factors that may limit MGDM transmission are identified. An optical method to reduce the spatial overlap among the fields of the detected mode groups could mitigate impairments that may occur in MGDM transmission. Mode-selective spatial filtering (MSSF) is such an optical method. Experimental results support that a robust five-channel MGDM system could be realized with MSSF, as long as modal noise is limited. MSSF facilitates the combination of MGDM with wavelength-division multiplexing.     

Explanatory Factors and Causality in the Dynamics of Volatility Surfaces Implied from OTC Asian–Pacific Currency Options

Volatility implied from observed option contracts systematically varies with the contracts’ strike price and time to expiration, giving rise to an instantaneously non-flat implied volatility surface (IVS) that exhibits substantial time variation. We identify a number of latent factors that drive the dynamics of the IVSs from options on 11 Asian–Pacific exchange rates and show that these have a natural interpretation in the law of motion of each surface. We present evidence that these latent factors are related due to their common dependence on exogenous economy-wide variables. Findings suggest that the factors capturing (i) the volatility level of the Japanese yen and the Chinese yuan, (ii) the volatility term structure of the Japanese yen, Taiwanese and Australian dollars and (iii) the risk aversion towards the Australian dollar, Japanese yen and Chinese yuan seem to incorporate first the investors’ expectations regarding the volatility in the region.     

Simultaneous Transmission of Millimeter-Wave and Baseband Signals Using Wavelength Interleaving and Polarization Multiplexing for an Integrated Reconfigurable Access Network

A novel scheme for the simultaneous transmission of 1.25-Gb/s baseband (BB) signals and 155-Mb/s 60-GHz radio-over-fiber (RoF) signals is experimentally demonstrated. The BB and RoF signals are wavelength-interleaved and polarization multiplexed. Tunable filtering along with polarization demultiplexing are used to drop an RoF signal with the wavelength-interleaved BB signal. This scheme is suited for future reconfigurable ring/bus access networks to provide an integrated platform for BB and millimeter-wave services.     

Temporal Stability of a Transparent Mode Group Diversity Multiplexing Link

The temporal behavior of a mode group diversity multiplexing (MGDM) link is examined. MGDM has been proposed as a way of creating parallel, independent communication channels over multimode fiber (MMF) links using different groups of modes. When the effect of dispersion can be neglected, the output electrical signals of an MGDM link are related to the input ones via a real-valued transmission matrix. The transmission matrix is vulnerable to changes in the modal spectrum of the propagating mode groups as well as to the coupling of light at the input and output of the MMF. Measurements of the transmission matrix of a two-input two-output system over 12.7 h show that an MGDM link can be very stable