Michelle C. Hauer

Higher order polarization mode dispersion compensation using a fixed time delay followed by a variable time delay

We propose and analyze a higher order polarization mode dispersion (PMD) compensator using a fixed differential group delay (DGD) section followed by a variable section. The performance limits of various PMD compensators are quantified and compared using dynamic PMD tracking. Compared with existing compensators with a single fixed DGD, the proposed compensator improves an nonreturn-to-zero 10-Gb/s link tolerance to average PMD from 28 to 44 ps. Alternatively, the tolerance increases to only 36 ps using a compensator with two fixed-DGD sections.

All-optical address recognition for optically-assisted routing in next-generation optical networks

Optical fiber communication technology enabled high-speed, long-distance capacity in todays networks. The packet switching functions such as address recognition and routing are performed in the electrical domain after optical-to-electrical conversion. As more real-time applications come online, demand for bandwidth increases, and electronic processing may potentially become a bottleneck at the intermediate nodes along the network. We introduce some optical address recognition schemes for optically-assisted routing that may decrease the processing delay at these nodes.

Practical Solutions to Polarization-Mode-Dispersion Emulation and Compensation

Polarization-mode dispersion (PMD) still remains a challenge for high-data-rate optical-communication systems. Practical solutions are desirable for PMD emulation, monitoring, and compensation. The authors review and compare various techniques for PMD emulation and compensation, with an emphasis on the application of programmable differential-group-delay (DGD) elements for manipulating PMD effects. The authors pay special attention to advanced emulation techniques, such as importance sampling and the hinge model, for practical applications. The tunability of programmable DGD elements proves to be attractive for both system performance evaluation and overall optimization

Polarization-mode-dispersion emulator using variable differential-Group-delay (DGD) elements and its use for experimental importance sampling

We demonstrate a practical polarization-mode-dispersion (PMD) emulator using programmable differential-group-delay (DGD) elements. The output PMD statistics of the emulator can be chosen by varying the average of the Maxwellian DGD distribution applied to each element. The emulator exhibits good stability and repeatability in a laboratory environment. In addition, we demonstrate how this emulator may be used to experimentally employ the powerful technique of importance sampling to quickly generate extremely low probability events. This technique is used to measure the Q-factor degradation due to both average and rare PMD values in a 10-Gb/s transmission system.

Electrically controllable all-fiber PMD emulator using a compact array of thin-film microheaters

An electrically controllable, all-fiber polarization-mode dispersion (PMD) emulator is constructed using thin-film microheaters to temperature tune the birefringence of 30 PM-fiber sections spliced at 45/spl deg/ angles. Compact packaging is achieved by mounting the fiber heaters onto an array of silicon V-grooves. The advantages of this electrically tunable emulator design are low loss, negligible PDL, simple construction, no internal reflections, and no moving parts.

Multiwavelength-channel header recognition for reconfigurable WDM networks using optical correlators based on sampled fiber Bragg gratings

We demonstrate a tunable, multiwavelength optical correlator that uses an array of sampled fiber Bragg gratings (FBGs) as the correlating element. The incoming wavelength-division-multiplexing (WDM) data streams are tapped off and the packet headers on each 10-Gb/s channel are simultaneously recognized and correlated to a reconfigurable header code. The correlation output for each channel is compared to a threshold level, and simple decision electronics are used to drive a set of switches to route the individual WDM packets accordingly. Using this technique, we recognize two WDM 10-Gb/s packet headers simultaneously, with a negligible power penalty when switching packets to the appropriate output port. Moreover, we tune the gratings for reconfigurable routing.

Compact, all-fiber PMD emulator using an integrated series of thin-film micro-heaters

We demonstrate a 30-section, compact, all-fiber polarisation mode dispersion (PMD) emulator that uses an integrated series of evaporated micro-heaters to thermally tune the birefringence of each differential group delay (DGD) section and accurately reproduce PMD statistics.

Dynamically reconfigurable all-optical correlators to support ultra-fast internet routing

To implement an effective optical bypass for an electronic router, the key design decision is to combine a software algorithm with a small set of dynamically configurable fiber-Bragg-grating based optical correlators. A conceptual diagram showing how the optical bypass is implemented in an IP router is shown.

High-speed, stable and repeatable PMD emulator with tunable statistics

Using three programmable DGD elements, we experimentally demonstrate a high-speed PMD emulator with tunable statistics and good stability and repeatability. By incorporating in-line polarimeters, a repeatable lookup-table of DGD and 2/sup nd/-order PMD states can be created.

Demonstration of multi-wavelength all-optical header recognition using a PPLN and optical correlators

We demonstrate multi-wavelength all-optical packet header recognition using a periodically-poled lithium niobate (PPLN) device and fiber Bragg grating arrays as optical correlators. The number of header recognition modules required in an optical cross-connect is drastically decreased by our method. We simultaneously recognize the header bits on two 2.5 Gbit/s WDM channels and route them to different output ports of a 2/spl times/2 cross-connect.