J.L. Zyskind

Two-wavelength WDM analog CATV transmission with low cross talk

We report a two-wavelength WDM analog CATV transmission system with cross talk <-60 dBc at launched power of +9 dBm/wavelength, an improvement of 13 dB over previous results. We are able to achieve this result principally by reducing the channel spacing from 8.6 nm to 2.2 nm. In addition, contrary to expectations for SRS, we find significant reduction of the cross talk by applying a 2-GHz dithering tone to the laser.

A gain-flattened ultra wide band EDFA for high capacity WDM optical communications systems

An 84 nm gain-flattened ultra wide band erbium-doped silica fiber amplifier for high capacity WDM optical communication systems is demonstrated with a noise figure of 6 dB and an output power of 25 dBm. We demonstrated an ultra wide band EDFA with a two-section, split band structure. The total 3dB bandwidth is 84.3 nm, which should be able to support 100 WDM channels with 100 GHz channel spacing or 200 WDM channels with 50 GHz channel spacing. The split bands allow independent optimization of each band for dispersion compensation and span loss variations.

Analytical formula for the transient response of erbium-doped fiber amplifiers.

In wavelength-division-multiplexing systems with optical amplifiers, channel drop or add can cause power changes in the existing channels. We present an analytical formula for the transient power of the existing channels as a function of time when one or more input channel is dropped or added on an erbium-doped fiber amplifier (EDFA). Although this formula was originally derived from perturbation theory of single-stage EDFAs, it is a good approximation of large-power excursion cases as well as two-stage EDFAs.

Relaxation oscillations and spectral hole burning in laser automatic gain control of EDFAs

Gain control to limit fast power transients in optical networks arising from optical amplifier cross saturation is a key issue related to wavelength-division multiplexing (WDM) networks. Here we consider the applicability of laser automatic gain control (AGC) to control fast power transients in optical networks and report the first high resolution measurements of transients in such gain-controlled erbium-doped fiber amplifiers (EDFAs).

Error free transmission of 64 WDM 10 Gb/s channels over 520 km of Truewave/sup TM/ fiber

We report error-free transmission of 64/spl times/10 Gb/s channels with 50 GHz spacing using high power, flat gain (35 nm bandwidth) erbium-doped silica fiber amplifiers. The amplifier spacing was 80-40 km, and the total end-of-system gain nonuniformity among the 64 channels was 6.4 dB.

Demonstration of a 16/spl times/10 Gb/s long-haul transmitter with 50-GHz channel spacing using two multifrequency lasers

A 16-wavelength transmitter with 50-GHz channel spacing was built by interleaving 2 externally modulated single-mode 8-channel waveguide-grating-router multifrequency lasers. Error-free transmission at 10 Gb/s for all 16 channels was measured through 595 km of true-wave fiber.