Lucent Technologies Inc.

At&t Bell Laboratories

Janice Bilecky Haber

Andrew Roman Chraplyvy

David Kalish

Harold Wayne Friesen

Wendell G Nutt

Bernard Raymond Eichenbaum

Raymond Bradfield Kummer

Gary Patrick Emery

A high-capacity optical fiber network &lsqb;,&rsqb; includes wavelength-division multiplexing (WDM) within the 1.4 micron (&mgr;m) wavelength region (i.e., 1335-1435 nm). Such a system includes optical fiber &lsqb;,&rsqb; whose peak loss in the 1.4 &mgr;m region is less than its loss at 1310 nm. The optical fiber has a zero dispersion wavelength (&lgr;,) at about 1310 nm, and linear dispersion between about 1.5 and 8.0 ps/nm-km within the 1.4 &mgr;m region. At least three WDM channels operate at 10 Gb/s in the 1.4 &mgr;m wavelength region and have a channel separation of 100 GHz. In one illustrative embodiment of the invention, a broadcast television channel, having amplitude modulated vestigial sideband modulation, simultaneously operates in the 1.3 &mgr;m region (i.e., 1285-1335 nm) and/or the 1.55 &mgr;m region (i.e., 1500-1600 nm). In another embodiment of the invention, 16 digital data channels are multiplexed together in the 1.55 &mgr;m region, each channel operating at about 2.5 Gb/s. Raman amplifiers &lsqb;,&rsqb; are used for amplification in the 1.3 &mgr;m and the 1.4 &mgr;m wavelength regions, whereas an Erbium amplifier &lsqb;,&rsqb; is used for amplification in the 1.55 &mgr;m wavelength region.

Arrangement of optical fiber segments for minimizing effect of nonlinearities

In a system (20) for transmitting voice and data signals, insulated metallic conductor pairs (44--44) which transmit data signals and insulated metallic conductor pairs (46--46) which are capable of transmitting voice signals are enclosed in a common sheath system of a single cable (40). User pickup of station apparatus (34) during the generation of a ringing voltage on a voice conductor pair causes that pair to become disturbing and to impart impulse noise to a closely coupled data pair. The data pair is designated a disturbed pair and the signals transmitted thereby may be affected adversely. This problem is overcome by providing a circuit (80) comprising in parallel a resistance and an inductance and being in series with the station apparatus. Such an arrangement reduces substantially that frequency content of any disturbing signal which appears on the disturbing pair and which is in the range of the data signal spectrum. This reduces the magnitude of crosstalk between the voice and data pairs and results in substantially error-free transmitted data.

Methods of and apparatus for providing substantially error-free

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Roswell, GA, United States of America

Janice Bilecky Haber