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We describe an experimental realization of ultralong-haul (ULH) networks with dynamically reconfigurable transparent optical add-drop multiplexers (OADMs) and optical cross-connects (OXCs). A simple new approach to dispersion management in ULH dense-wavelength-division-multiplexing (DWDM) transparent optical networks is proposed and implemented, which enables excellent transmission performance while avoiding dispersion compensation on a connection-by-connection basis. We demonstrate "broadcast-and-select" node architectures that take full advantage of this method. Our implementation of signal leveling ensures minimum variations of path-averaged power among the wavelength-division-multiplexing (WDM) channels between the dynamic gain-equalizing nodes and results in uniform nonlinear and spontaneous-emission penalties across the WDM spectrum. We achieve 80 10.7-Gb/s DWDM networking over 4160 km (52 spans 80 km each) of all-Raman-amplified symmetric dispersion-managed fiber and 13 concatenated OADMs or 320 320 wavelength-port OXCs with 320-km node spacing. The WDM channels use 50-GHz grid in band and the simple nonreturn-to-zero (NRZ) modulation format. The measured values exhibit more than a 1.8-dB margin over the forwarderror correction threshold for 10 15 bit-error-rate operation. We compare these results with point-to-point transmission of 80 10-Gb/s NRZ WDM signals over 4160 km without OADM/ OXC and provide detailed characterization of penalties due to optical signal-to-noise-ratio degradation, filter concatenation, and crosstalk. Index Terms-Add-drop multiplexer, dispersion management, optical communication, optical cross-connect (OXC), Raman amplification, transparent optical networks. I. INTRODUCTION T RANSPARENT ultra-long-haul (ULH) network systems have gained strong importance in the past few years, as the longer transparent reach distance of optical circuit connection promises network cost reduction through elimination of costly optical-to-electrical-to-optical (O/E/O) data regenerators.

The optical properties of a coherent array of 300 nm SiO2 spheres implanted with Si ions were shown to change nonlinearly with light intensity. These changes have been attributed to transverse confinement of the optical beam within the opal structure.

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A coherent array of silica spheres, which was implanted with erbium ions, showed nonlinear behavior at λ=0.532 μm. This was attributed to a large nonlinear refraction effect, which was enhanced by the structure of the opaline matrix. In addition, near infrared photoluminescence measurements showed an overall enhancement as a function of the sphere’s size. A large photoluminescence peak was found around λ=900 nm and attributed to the lensing effect of the opaline matrix.