G. Raybon

2.5 Tb/s (64/spl times/42.7 Gb/s) transmission over 40/spl times/100 km NZDSF using RZ-DPSK format and all-Raman-amplified spans

We report 2.5 Tb/s (64 /spl times/ 42.7-Gb/s) WDM transmission over 4000 km (forty 100-km spans) of non-zero dispersion-shifted fiber. This capacity /spl times/ distance record of 10 petabit-km/s for 40-Gb/s systems is achieved in a single 53-nm extended L band using return-to-zero differential-phase-shift-keyed modulation, balanced detection, and distributed Raman amplification.

A 16*1 wavelength division multiplexer with integrated distributed Bragg reflector lasers and electroabsorption modulators

The integrated operation of a 16*1 wavelength-division-multiplexed (WDM) source with distributed Bragg reflector (DBR) lasers and electroabsorption modulators has been demonstrated. By using repeated holographic exposures and wet chemical etching, 16 different wavelengths from 1.544 to 1.553 mu m with an average channel spacing of 6 AA are obtained. A high-performance combiner is used to obtain a very uniform coupling into the single-output waveguide, and with the integration of an optical amplifier an average optical power of -8 dBm per channel is coupled into a single-mode fiber.<<ETX>>

100-Gb/s DQPSK Transmission: From Laboratory Experiments to Field Trials

We discuss the generation, detection, and long-haul transmission of single-polarization differential quadrature phase shift keying (DQPSK) signals at a line rate of 53.5 Gbaud to support a net information bit rate of 100 Gb/s. In the laboratory, we demonstrate 10-channel wavelength-division multiplexed (WDM) point-to-point transmission over 2000 km on a 150-GHz WDM grid, and 1200-km optically routed networking including 6 reconfigurable optical add/drop multiplexers (ROADMs) on a 100-GHz grid. We then report transmission over the commercial, 50-GHz spaced long-haul optical transport platform LambdaXtremereg. In a straight-line laboratory testbed, we demonstrate single-channel 700-km transmission, including an intermediate ROADM. On a field-deployed, live traffic bearing Verizon installation between Tampa and Miami, Florida, we achieve 500-km transmission, with no changes to the commercial system hardware or software and with 6 dB system margin. On the same operational system, we finally demonstrate 100-Gb/s DQPSK encoding on a field-programmable gate array (FPGA) and the transmission of real-time video traffic.

Linear optical sampling

We demonstrate the measurement of waveforms and eye diagrams at high bit rates by optical sampling using coherent detection. By simultaneously recording two orthogonal quadratures of the interference between the data stream and a sampling pulse with two balanced detectors, we are able to cancel the phase sensitivity inherent to linear optics. As the device is based on linear optics and square-law low-speed photodetectors, its sensitivity is 1000 times better than nonlinear optical sampling techniques, which makes it attractive for optical signal characterization and monitoring. This new diagnostic tool was used to measure eye diagrams at 10, 40, and 80 Gb/s, and is projected to operate at 160 Gb/s and higher.

Characterization of erbium-doped fibers and application to modeling 980-nm and 1480-nm pumped amplifiers

Erbium-doped fibers are characterized using loss and gain coefficients, and one amplifier saturation parameter. With a large-signal amplifier model that resolves the amplified spontaneous emission spectrum, these easily measured parameters allow the fiber performance in 980-nm or 1480-nm pumped optical amplifiers to be assessed rapidly. In tests at 980-nm pump wavelength, good agreement between the theoretical and experimentally measured gains was obtained with amplifiers having either germano-silicate or germano-alumino-silicate core fibers.<<ETX>>

Transform‐limited 1.4 ps optical pulses from a monolithic colliding‐pulse mode‐locked quantum well laser

We report the generation of short optical pulses from novel monolithic colliding‐pulse mode‐locked quantum well lasers. Transform‐limited pulses with durations of 1.4 ps at a repetition rate of 32.6 GHz have been achieved, with nearly 100% intensity modulation depth and a peak optical power of 10 mW. This is the shortest transform‐limited pulse directly generated from monolithic mode‐locked lasers (time‐bandwidth product =0.3).

Single-port laser-amplifier modulators for local access

We describe a single-port, reflective, waveguide modulator based on semiconductor laser amplifier technology. The single-port geometry reduces the high packaging cost associated with two-port waveguide modulators, while the internal gain of the amplifier compensates for splitting and coupling losses. A modulator with a bulk active layer showed a reflection-mode chip gain of 17 dB at /spl lambda/=1.56 /spl mu/m. When driven with pseudorandom digital data at 100 Mb/s, extinction ratios of >12 dB were observed over the broad wavelength range (20 nm) needed for wavelength division multiplexed systems. Bit-error-rate tests confirmed that there was no distortion penalty, compared to a LiNbO/sub 3/ reference modulator.

1-Tb/s (6 x 170.6 Gb/s) transmission over 2000-km NZDF using OTDM and RZ-DPSK format

We demonstrate six-channel 160-Gb/s wavelength-division-multiplexed transmission over 20 100-km spans of nonzero-dispersion fiber, with a spectral efficiency of 0.53 b/s/Hz. We achieve this result using optical-time-division multiplexing with polarization bit interleaving and return-to-zero differential-phase-shift-keying modulation format. We also operate at 170.6 Gb/s per channel to emulate the use of forward error correction.

All-fiber grating-based higher order mode dispersion compensator for broad-band compensation and 1000-km transmission at 40 Gb/s

We use a novel fiber-grating device to demonstrate the first polarization-insensitive all-fiber higher order mode dispersion compensator for broad-band dispersion compensation. Its low loss and high effective area have enabled transmission through 1000 km (10/spl times/100 km) of nonzero dispersion-shifted fiber (NZDSF) at 40 Gb/s.

InP-based multiple quantum well lasers with an integrated tapered beam expander waveguide

We demonstrate the integration of a laterally tapered adiabatic mode expander waveguide inside the cavity of diode lasers operating at 1.3 and 1.55 /spl mu/m wavelengths. This integration results in narrow output beam divergence with FWHM of 70 and 50 vertically and laterally respectively. The loss caused by the passive waveguide is minor and for devices operating at 1.55 (1.3) /spl mu/m threshold currents as low as 12 (22) mA and quantum efficiencies as high as 52% (51%) are obtained. Coupling to a cleaved optical fiber yields broad alignment tolerance with 1 dB excess loss for misalignment of /spl plusmn/2.6 /spl mu/m vertically and /spl plusmn/3.1 /spl mu/m laterally, with a minimum coupling loss of -3.5 dB.<<ETX>>