Rainer Hainberger

Comparison of span configurations of Raman-amplified dispersion-managed fibers

We evaluate the performance of dispersion-managed fiber transmission systems employing distributed Raman amplification with 50- and 100-km span length for three different span configurations. The evaluation considers the optical signal-to-noise ratio and the nonlinear phase shift as a measure for the impact of nonlinear effects. The simulation results indicate that a 100-km-long span with the dispersion compensating fiber placed in the span center achieves the best tradeoff between optical signal-to-noise degradation and nonlinear effects.

BER estimation in optical fiber transmission systems employing all-optical 2R regenerators

A bit error rate estimation method for optical fiber transmission systems employing all-optical 2R regenerators is presented. The method is based on the linearization of the nonlinear transfer function of the regenerators in three sections. Using this linearized three-section model, the impact of 2R regeneration on the system performance as a function of the extinction ratio, the clamping factor, and the steepness of the transfer function is studied.

Impact of the wavelength dependence of the mode field on the nonlinearity coefficient of PCFs

We theoretically analyze the impact of the wavelength dependence of the optical mode-field distribution on the nonlinearity coefficient /spl gamma/ for photonic crystal fibers with square and hexagonal air-hole lattices and for a silica rod. For the core size, which provides the maximum achievable nonlinearity coefficient, the relative change of /spl gamma/ over a 60-nm wavelength range around 1550 nm amounts to approximately 12.5%.

Optimum span configuration of Raman-amplifier dispersion-managed fibers

We analyze the influence of the span structure on the performance of Raman-amplified dispersion-managed fibers. Our calculations show that a configuration with the dispersion compensating fiber placed in the span center achieves the best trade-off between optical signal-to-noise ratio and nonlinear effects.

Micro-Optical Platform for All-Optical Demultiplexing Switch Array

As it is free from electrical parasitics, the use of the all-optical switch array is an attractive approach for achieving very high-speed signal processing for optical communication and interconnection beyond the Gbit/s range. However, two incident beams and one outgoing beam for each switch may require a complex geometry, thus the module assembly procedure remains a serious obstacle for its realization. The present work reports the design, test fabrication, and characterization of an optical platform dedicated to all-optical demultiplexing at 1.55 µm, using asymmetric Fabry-Perot saturable absorber switches as active devices, and off-axis binary Fresnel zone lenses as the focusing optics. Two different platform configurations were fabricated by a substrate stacking technique achieving spot sizes of 13 µm and 22.5 µm at the switch plane, with reasonable overlap between the pump and signal beams. The influence of wavelength variation, fabrication tolerance and throughput are discussed.

43-Gbit/s/spl times/40 ch transmission over 1,600 km of conventional single-mode fiber in NRZ modulation scheme

We demonstrate the feasibility of economical 40-Gbit/s WDM transmission over 1,600-km conventional single-mode fiber with simple NRZ modulation scheme employing two-stage dispersion compensating fiber Raman amplification and optimised dispersion map with excessive in-line dispersion compensation.

All-optical switching module based on diffractive optics technology

To support the rapid growth of communication traffic in information age, all optical node technology is vitally needed. The present review summarizes the design consideration, the fabrication procedures and the result of the test experiments. Major technical issues toward the realistic development of all optical switching modules are listed and the possible solutions are discussed.