Olivier Jerphagnon

All-optical label swapping networks and technologies

All-optical label swapping is a promising approach to ultra-high packet-rate routing and forwarding directly in the optical layer. In this paper, we review results of the DARPA Next Generation Internet program in all-optical label swapping at University of California at Santa Barbara (UCSB). We describe the overall network approach to encapsulate packets with optical labels and process forwarding and routing functions independent of packer bit rate and format. Various approaches to label coding using serial and subcarrier multiplexing addressing and the associated techniques for label erasure and rewriting, packet regeneration and packet-rate wavelength conversion are reviewed. These functions have been implemented using both fiber and semiconductor-based technologies and the ongoing effort at UCSB to integrate these functions is reported. We described experimental results for various components and label swapping functions and demonstration of 40 Gb/s optical label swapping. The advantages and disadvantages of using the various coding techniques and implementation technologies are discussed.

Three-dimensional MEMS photonic cross-connect switch design and performance

Photonic cross-connects (PXC) play a key role in all-optical transparent networks. In this paper, the optical design and modeling of a three-dimensional microelectromechanical system (3-D MEMS) based optical switch are discussed. Basic design rules and considerations are reviewed and used to determine the optimum configuration for free-space optical switches with more than 300 ports. The optical performance of a 256 /spl times/ 256 PXC system, including a 347 /spl times/ 347 nonblocking core switch and auxiliary 2 /spl times/ 2 optical switches for 1:1 protection and optical taps for power monitoring, is presented. The core switch has 1.4-dB median insertion loss, 1.5-dB wavelength dependent loss across a broadband of 1260-1625 nm, and a typical polarization dependent loss of 0.1 dB. Environmental tests including temperature and vibration are described.

Optical SCM data extraction using a fiber-loop mirror for WDM network systems

We demonstrate the use of a polarization-independent dual-port filter to extract subcarrier multiplexed (SCM) data from a baseband/SCM channel while the baseband is passed through with minimal distortion. This architecture solves the fiber dispersion-induced fading problem for SCM channels and eliminates the complexity of single-sideband modulation techniques by suppressing the optical carrier at the tap port prior to photodetection. Bit-error-rate (BER) measurements were performed on the baseband channel showing that the SCM removal prior to photodetection reduces crosstalk with the subcarrier channel. The BER on the SCM data shows no effect of dispersion-induced fading. The periodic optical frequency characteristic of the filter can be matched to the ITU grid, making this tap applicable to multichannel WDM networks.

Applications of large-scale optical 3D-MEMS switches in fiber-based broadband-access networks

Applications of non-blocking large-scale optical switches based on three-dimensional micro-electro-mechanical system (3D-MEMS) technology with small size and low power consumption are described for fiber-based broadband access networks. The low-loss and fast-switching 3D-MEMS switches offer remotely reconfigurable and automated operational solutions for access networks such as fiber management, preventative maintenance, monitoring, testing, and troubleshooting of a large number of end customers. Furthermore, the wavelength, data rate, and protocol-transparent nature of 3D-MEMS switches results in a future-proof optical distribution network design for future higher speed and higher capacity wavelength division multiplexing overlay upgrades over the passive optical network (PON). We show that large-scale 3D-MEMS switches deployed in PON environments can offer over an order of magnitude in capital and operational savings in comparison to manual patch panels (in deployed fiber hardware, real estate, and manual labor) with minimal impact on the overall network design.

A cyclic MUX-DMUX photonic cross-connect architecture for transparent waveband optical networks

A novel photonic cross-connect (PXC) configuration with cyclic multiplexers and demultiplexers (DMUXs) is proposed for realizing dynamic switching and transparent add-drop in waveband dense wavelength-division-multiplexed networks. The PXC architecture allows for a flexible operation while maintaining low optical losses for express wavebands and add-drop wavelengths. The drop functionality of this architecture is demonstrated using an integrated cyclic optical DMUX and four 10-Gb/s PIN receivers with an average receiver sensitivity of -34 dBm as a compact and cost-effective solution.

A 32/spl times/10 Gb/s DWDM metropolitan network demonstration using wavelength-selective photonic cross-connects and narrow-band EDFAs

The feasibility of a 32/spl times/10 Gb/s dense wavelength-division-multiplexed (DWDM) all-optical short-reach metropolitan network using dynamically reconfigurable three-dimensional microelectromechanical-system-based wavelength-selective photonic cross-connects (WSPXC) is experimentally investigated. Full DWDM amplification at the high-capacity node is performed with low-cost narrow-band erbium-doped fiber amplifiers whose channel gain variation is compensated per span using the inherent channel equalization capability of the WSPXC. With Reed-Solomon forward error correction, bit-error rates better than 10/sup -15/ are possible for all 32 channels over 400 km of single-mode fiber and ten transitions through the WSPXC nodes.

Cascadability of large-scale 3-D MEMS-based low-loss photonic cross-connects

The performance of cascaded low-loss (<3.5 dB) 256/spl times/256 three-dimensional microelectromechanical system (3-D MEMS) photonic cross-connects (PXCs) is experimentally investigated in a recirculating loop. After 60 transitions through the PXC, a power penalty of 1.7 dB is observed, which is attributed to the accumulation of the low polarization-dependent loss in the optical switch. The use of 3-D MEMS PXCs as a wavelength-selective switch (WSPXC) for transparent all-optical networks is also demonstrated. Measured Q-factors for all 16 100-GHz-spaced wavelengths at 10 Gb/s over eight spans of 75-km single-mode fiber and eight transitions through the WSPXC nodes are better than 17 dB.

Performance and applications of a large port-count and low-loss photonic cross-connect system for optical networks

We report a 256/spl times/256 photonic cross-connect system including 1:1 protection and under 7dB insertion loss in the O and C bands. Some performance metrics are more or less important depending on the application but high reliability and low insertion loss are common requirements for network deployment. Although a 3D-MEMS based PXC is highly linear and transparent, its impact on the optical reach when several nodes are cascaded without electrical regeneration cannot be neglected. A metric is proposed to measure the performance and transparency of a PXC in an all-optical network: the ratio of the bandwidth /spl times/ distance products given by B.L(N)/B/sub 0/.L/sub 0/.

Optical SCM data extraction using a fiber loop mirror for WDM network systems

We demonstrate the use of a polarization-independent dual-port filter to extract subcarrier multiplexed (SCM) data from a baseband/SCM channel while the baseband is passed through with minimal distortion. This architecture solves the fiber dispersion-induced fading problem for SCM channels and eliminates the complexity of single-sideband modulation techniques by suppressing the optical carrier at the tap port prior to photodetection. Bit-error-rate (BER) measurements were performed on the baseband channel showing that the SCM removal prior to photodetection reduces crosstalk with the subcarrier channel. The BER on the SCM data shows no effect of dispersion-induced fading. The periodic optical frequency characteristic of the filter can be matched to the ITU grid, making this tap applicable to multichannel WDM networks.

Large optical 3D MEMS switches in access networks

Interest is high among residential customers and businesses for advanced, broadband services such as fast Internet access, electronic commerce, video-on-demand, digital broadcasting, teleconferencing and telemedicine. In order to satisfy such growing demand of end-customers, access technologies such as fiber-to-the-home/building (FTTH/B) are increasingly being deployed. Carriers can reduce maintenance costs, minimize technology obsolescence and introduce new services easily by reducing active elements in the fiber access network. However, having a passive optical network (PON) also introduces operational and maintenance challenges. Increased diagnostic monitoring capability of the network becomes a necessity as more and more fibers are provisioned to deliver services to the end-customers. This paper demonstrates the clear advantages that large 3D optical MEMS switches offer in solving these access network problems. The advantages in preventative maintenance, remote monitoring, test and diagnostic capability are highlighted. The low optical insertion loss for all switch optical connections of the switch enables the monitoring, grooming and serving of a large number of PON lines and customers. Furthermore, the 3D MEMS switch is transparent to optical wavelengths and data formats, thus making it easy to incorporate future upgrades, such higher bit rates or DWDM overlay to a PON.