Paul Colbourne

Tunable dispersion and dispersion slope compensators for 10 Gb/s using all-pass multicavity etalons

We propose and demonstrate a novel approach to multichannel tunable dispersion compensation based on multicavity etalons that can compensate all channels throughout the C- or L-band with either 50- or 100-GHz channel spacings for 10-Gb/s applications. We demonstrate very low group delay ripple, large tuning range, as well as dispersion slope compensation for LEAF and TrueWave RS fiber across the L-band. In addition, we indicate that scaling the bandwidth for 40-Gb/s applications is readily achievable.

Tunable dispersion compensation at 40-Gb/s using a multicavity etalon all-pass filter with NRZ, RZ, and CS-RZ modulation

We present a multichannel tunable dispersion compensator (TDC) based on multicavity all-pass etalons that is capable of operation at 40 Gb/s. The device has a tuning range of +200/-220 ps/nm with a group delay ripple < /spl plusmn/5 ps over a channel bandwidth of 80 GHz, an overall loss of < 5.2 dB, very low insertion loss ripple, and can operate on any channel on a 200-GHz grid over the C-band. In addition, we present system performance results at 40 Gb/s using NRZ, RZ, and CS-RZ modulation, compensating up to 45 km of nonzero dispersion shifted fiber (NZDSF). Our results show that this device introduces very little excess system penalty with signal frequency drifts of up to 20 GHz when operated near the center of its tuning range. For single channel experiments with fiber, the system penalty increase versus signal detuning is more significant, but can be reduced by dynamically optimizing the device dispersion during detuning. Finally, we demonstrate simultaneous compensation of 4 channels across the C-band over 25 km of NZDSF.

WSS Switching Engine Technologies

Various switching engines such as MEMS, liquid crystal, and phased arrays, can be used to implement a colorless WSS. Switching engine affect on device design characteristics and implications on specifications for future applications are discussed.

Multichannel tunable dispersion compensation using all-pass multicavity etalons

We have proposed and demonstrated a novel approach to multi-channel tunable dispersion compensation using all-pass multi-cavity etalon filters for 10 Gb/s applications.

Digital laser microinterferometer and its applications

A universal digital laser microinterferometer is presented, which can measure the shape, displacement, and strain and stress of microelements and microelectromechanical systems (MEMSs). This device can measure microelements with either a smooth or a rough surface. The method is based on laser interferometry (for smooth surfaces) and laser speckle interferometry (for rough surfaces), incorporating a diode laser, a long-distance microscope, a CCD camera, and a high-precision phase-shifting technique. The measuring system can be utilized to measure shape and out-of-plane displacement for samples with smooth surfaces, and with minor modification it can be applied to investigate out-of-plane and in-plane displacements for samples with rough surfaces. The theory and methodology of the universal digital laser microinterferometer are described. In particular, calibration and error compensation are introduced. The usefulness of the microinterferometer is demonstrated by examples of shape and displacement measurement for different MEMSs and microelements.

Addressing Manufacturability and Reliability of MEMS-based WSS

Initial design-in of WSS-based modules posed many uncertainties due to several technology firsts. We discuss key challenges and steps taken to successfully complete qualification and validation and will demonstrate the level of stability achieved.

Tunable dispersion compensation at 10 Gb/s and 40 Gb/s using multicavity all-pass etalons

Our tunable dispersion compensator devices based on multiple cavity all-pass etalons are designed to compensate all channels throughout the C- and L-bands and appropriate for 10 Gb/s and 40 Gb/s applications. Detailed characterization of devices and system experimental results will be presented.

Generally astigmatic Gaussian beam representation and optimization using skew rays

Methods are presented of using skew rays to optimize a generally astigmatic optical system to obtain the desired Gaussian beam focus and minimize aberrations, and to calculate the propagating generally astigmatic Gaussian beam parameters at any point. The optimization method requires very little computation beyond that of a conventional ray optimization, and requires no explicit calculation of the properties of the propagating Gaussian beam. Unlike previous methods, the calculation of beam parameters does not require matrix calculations or the introduction of non-physical concepts such as imaginary rays.