A. Lucero

Transmission of 96×100G pre-filtered PDM-RZ-QPSK channels with 300% spectral efficiency over 10,608km and 400% spectral efficiency over 4,368km

We transmitted 96 × 100 G pre-filtered PDM-RZ-QPSK channels with 300% spectral efficiency over 10,608 km using 52 km spans of 150 μm2 fiber and simple single-stage EDFAs. We also achieved 400% spectral efficiency over 4,368 km using similar techniques.

RZ-DPSK field trial over 13,100 km of installed non slope-matched submarine fibers

This work presents the first field trial using the return-to-zero differential-phase-shift-keying (RZ-DPSK) modulation format. A 96/spl times/10-Gb/s RZ-DPSK field trial was conducted over a 13 100-km optical undersea path by double passing the installed 6550-km underwater link which was deployed with non-slope-matched submarine fibers. All channels performed with more than a 3-dB forward-error correction margin, including channels that accumulated over /spl plusmn/13 000ps/nm of dispersion. It is also shown that the RZ-DPSK format has similar residual dispersion and channel power tolerance for both slope-matched and non-slope-matched fibers. Furthermore, it is demonstrated that the chirped RZ-DPSK format could further improve system performance by 1-2 dB.

40 Gb/s WDM Transmission of Eight 5 Gb/s Data Channels Over Transoceanic Distances using the Conventional NRZ Modulation Format

The transmission of many Wavelength Division Multiplexed (WDM) channels over transoceanic distances can be limited by the nonlinear interactions between channels. In this work the nonlinear interactions were suppressed by tailoring the chromatic dispersion of the transmission fiber1 and operating the system at low channel power. These techniques made possible the transmission of eight 5 Gb/s Non-Return-to-Zero (NRZ) channels over 8000 km for a total transmission capacity of 40 Gb/s.

Long-haul 40 Gb/s DWDM transmission with aggregate capacities exceeding 1 Tb/s

We present an experimental investigation of 40 Gb/s transmission technology aimed at an aggregate capacity exceeding 1 Tb/s over multithousand kilometer transmission distances. These studies have been performed using a variety of dispersion management and modulation techniques. The transmission distances investigated range from a minimum of 2000 km, which is considered a regional undersea cable distance, up to a transatlantic distance of 6200 km. Our regional distance experiments were performed using both slope-matched and conventional dispersion maps where the accumulated dispersion becomes large for the edge channels. Dispersion map studies showed that slope-matched fiber performs better than nonslope-matched fiber (NZDSF) beyond 2000 km due to its larger effective area and lower accumulated dispersion slope. The demonstration of 38/spl times/40 Gb/s over 6200 km was the first transoceanic length experiment using 40 Gb/s DWDM channels. This was achieved with a relatively simple amplifier chain that uses only C-band EDFAs. Modulation format studies showed that RZ performs better over transoceanic distance, carrier-suppressed RZ performs better with nonslope-matched fiber at a distance of 2055 km, and prefiltered carrier-suppressed RZ is more suited for higher spectral efficiency. Experimental techniques for high bit-rate experiments are presented.

112×112 Gb/s transmission over 9,360 km with channel spacing set to the baud rate (360% spectral efficiency)

We transmit 112×112 Gb/s pre-filtered PDM RZ-QPSK channels with 360% spectral efficiency over 9,360km with the channel spacing set to the baud rate. This results in a record spectral efficiency for transpacific distance.

High spectral efficiency long-haul transmission with pre-filtering and maximum a posteriori probability detection

We propose a high spectral efficiency transmission scheme employing tight pre-filtering and maximum-a-posteriori-probability (MAP) detection. We demonstrate that pre-filtering induced inter-symbol-interference can be effectively compensated with MAP detection after transoceanic transmission.

2.4 Tb/s (120 /spl times/ 20 Gb/s) transmission over transoceanic distance using optimum FEC overhead and 48 % spectral efficiency

We have demonstrated 2.4 Tb/s (120 /spl times/ 20 Gb/s) transmission over the transoceanic distance of 6,200 km using optimum forward error correction (FEC) code overhead, 48% spectral efficiency, ultra-low slope dispersion map, and full C-band EDFAs.

Transmission of thirty-eight 40 Gb/s channels (>1.5 Tb/s) over transoceanic distance

Thirty-eight 40 Gb/s channels were transmitted over 6,200 km for a total capacity of 1.52 Tb/s. This is the first transoceanic length DWDM demonstration using 40 Gb/s channels. In addition, we show 60% spectral efficiency over 4,500 km without the need of polarization demultiplexing.

Experimental comparison of the RZ-DPSK and NRZ-DPSK modulation formats

The RZ-DPSK and NRZ-DPSK modulation formats were experimentally compared using installed undersea fiber links. Our results show a 1-1.5 dB RZ benefit with optimized RZ modulation depth for both 25-GHz and 33-GHz spaced channels.

Improved Margin in Long-Haul 40 Gb/s Systems Using Bit-Synchronously Modulated RZ-DQPSK

We demonstrated a substantial improvement in FEC margin at 40 Gb/s using bit-synchronously modulated RZ-DQPSK. We transmitted 28×40 Gb/s CRZ-DQPSK channels over 6,550 km with ~2 dB of actual FEC margin, without any PMD compensation.