Lynn E. Nelson

Jones matrix for second-order polarization mode dispersion

A Jones matrix is constructed for a fiber that exhibits first- and second-order polarization mode dispersion (PMD). It permits the modeling of pulse transmission for fibers whose PMD vectors have been measured or whose statistics have been determined by established PMD theory. The central portion of our model is a correction to the Bruyère model.

Coherent crosstalk impairments in polarization multiplexed transmission due to polarization mode dispersion.

Coherent crosstalk mechanisms induced by polarization mode dispersion in polarization multiplexed fiber transmission are examined by systems experiments, analysis and supporting modeling. Primary mechanisms include destructive interference, edge effects, and beat effects, leading to pulse distortion and to bit-error-rate penalties. Rules of thumb for tolerable crosstalk levels are developed.

Measurement of polarization mode dispersion vectors using the polarization-dependent signal delay method

We describe a new time-domain method for determining the vector components of polarization-mode dispersion from measurements of the mean signal delays for four polarization launches. Using sinusoidal amplitude modulation and sensitive phase detection, we demonstrate that the PMD vector components measured with the new method agree with results obtained from the more traditional Müller Matrix Method.

10-Gb/s upgrade of bidirectional CWDM systems using electronic equalization and FEC

We discuss options for upgrading coarse wavelength-division multiplexed (CWDM) optical access links over standard single-mode fiber (SSMF) by increasing per-channel data rates from 2.5 to 10 Gb/s. We identify electronic equalization and forward error correction (FEC) as the enabling technologies to overcome the dispersion limit of SSMF. In addition, we show how FEC enhances the tolerance to in-band crosstalk, and paves the way toward fully bidirectional CWDM transmission. Due to the lack of CWDM sources rated for 10-Gb/s operation, we demonstrate full-spectrum (1310 to 1610 nm) 10-Gb/s CWDM transmission over standard-dispersion fiber using uncooled, directly modulated lasers specified for 2.5 Gb/s. All 16 CWDM channels could be transmitted over more than 40 km, yielding a capacity-times-distance product of 6.4 Tb/s/km. The longest transmission distance (80 km) was achieved at 1610 nm, equivalent to 1600 ps/nm of chromatic dispersion.

Relative impact of multiple-path interference and amplified spontaneous emission noise on optical receiver performance

In this paper we compare the impact of MPI and ASE noise on Q-factor measurements when using an optically-preamplified receiver. We performed measurements on a 10-Gb/s data stream for two transmission formats: return-to-zero with a 50% duty cycle and a nonreturn-to-zero.

WDM transmission over multiple long spans with bidirectional Raman pumping

We investigate the feasibility of WDM transmission over multiple spans that are twice as long as those typically used in commercial systems. Using longer spans reduces the number of repeater sites, potentially lowering the operating costs of medium- and long-haul terrestrial systems. We show that bidirectional Raman pumping is a key enabling technology. In particular, we demonstrate the benefits of high levels of codirectional Raman gain, up to 10-dB more than is used in transmission experiments with standard span lengths. Then, we transmitted 40 /spl times/ 10.66 Gb/s with uncorrected bit-error ratios better than 10/sup -9/ using 200-km spans of nonzero dispersion fiber with 14.5-dB of Raman co-gain over a reach of 2400 km. We also measured the maximum amount of span loss that was tolerable for a given system reach for 200-km span transmission at 10 Gb/s. After optimization at twelve distances (800 to 3000 km), we found that the tolerable span loss increased by 1 dB for each 200-km reduction in reach.

Transmission of 1.6 Tb/s (40/spl times/42.7 Gb/s) over transoceanic distance with terrestrial 100-km amplifier spans

Forty 42.7-Gb/s, 100-GHz-spaced WDM channels were transmitted over 6000 km of Ultra-Wave/spl trade/ fiber using 100-km dispersion-managed fiber spans. This is the first transoceanic length DWDM demonstration at 40 Gb/s using terrestrial amplifier span lengths.

Experimental investigation of the impact of NZDF zero-dispersion wavelength on broadband transmission in Raman-enhanced systems

Two nonzero dispersion fibers with different zero-dispersion wavelengths (ZDW) were evaluated for C+L-band, Raman-enhanced systems. With an optimized ZDW, 80/spl times/42.7 Gb/s transmission over 800-km can be achieved without forward-error-correction or per-channel post dispersion optimization.

40-Gb/s transmission over 2000 km of nonzero-dispersion fiber using 100-km amplifier spacing

Pseudo-linear transmission over 2000 km at 40-Gb/s is demonstrated with 100-km amplifier spacing and without using FEC. A simple optimized dispersion map based on conventional terrestrial link design is used to increase the non-linearity threshold enabling higher signal powers to be launched. A Q-value of 15.9 dB is measured after transmission over 2000-km transmission line using 2-dBm launched signal power.

70 nm seamless band transmission of 17.3 Tb/s over 40×100km of fiber using complementary Raman/EDFA

We demonstrated 70nm seamless band transmission of 173×128Gb/s QPSK signals over 40×100km of TeraWave™ fiber. The complementary Raman/EDFAs and wide-band single-stage discrete Raman amplifiers were used to achieve this 17.3Tb/s capacity ultra-wide single-band transmission.