Energy-efficient 0.26-Tb/s coherent-optical OFDM transmission using photonic-integrated all-optical discrete Fourier transform

We propose a novel energy-efficient coherent-optical OFDM transmission scheme based on hybrid optical-electronic signal processing. We demonstrate transmission of a 0.26-Tb/s OFDM superchannel, consisting of 13 x 20-Gb/s polarization-multiplexed QPSK subcarrier channels, over 400-km standard single-mode fiber (SSMF) with BER less than 6.3x10(-4) using all-optical Fourier transform processing and electronic 7-tap blind digital equalization per subchannel. We further explore long-haul transmission over up to 960 km SSMF and show that the electronic signal processing is capable of compensating chromatic dispersion up to 16,000 ps/nm using only 15 taps per subchannel, even in the presence of strong inter-carrier interference.

Long-haul transmission of 35-Gb/s all-optical OFDM signal without using tunable dispersion compensation and time gating

We propose that the optical OFDM technique using all optical discrete Fourier transform (DFT) has potential as a viable alternative for upgrading long-haul optical transmission systems towards 100-Gb/s. We demonstrate transmission of 35-Gb/s (7 x 5 Gb/s NRZ-OOK) all-optical OFDM signal over ~2000-km dispersion-managed span without using tunable dispersion compensation and time gating. We achieve bit error ratio of 1.2x10(-3) (7x10(-3)) for transmission over 1980-km (2310-km) all-EDFA amplified span consisting of standard single mode fiber (SSMF) and dispersion compensating fiber (DCF). We also study the nonlinear penalty impacting the all-optical OFDM transmission and discuss potential method for its mitigation.

All-optical OFDM transmission of 7 x 5-Gb/s data over 84-km standard single-mode fiber without dispersion compensation and time gating using a photonic-integrated optical DFT device

We implement dispersion-tolerant and time-gating-free all-optical OFDM transmission using a photonic-integrated discrete Fourier transform (DFT) device. We show that 35-Gb/s OFDM data having near-unity spectral efficiency can be transmitted all-optically with 1-dB dispersion margin of ~1000 ps/nm. The passive-optical DFT circuit is implemented using multi-mode interference (MMI) couplers on a high index-contrast silica integrated-optic platform. We also propose a photonic DFT circuit based on an NxN MMI device capable of simultaneous channelization of OFDM signals into N subcarriers.

All-optical XOR and XNOR operations at86.4 Gb/s using a pair of semiconductor optical amplifier Mach-Zehnder interferometers

We propose a method for increased-speed all-optical XOR operation using semiconductor optical amplifiers. We demonstrate XOR and XNOR operations at 86.4 Gb/s using a pair of photonic-integrated semiconductor optical amplifier Mach-Zehnder interferometers.

A hybrid electroabsorption modulator device for generation of high spectral-efficiency optical modulation formats

We report a novel hybrid integrated optic device consisting of AlGaInAs/InP electroabsorption modulators and a four-arm silica-on-silicon planar lightwave circuit optical interferometer. The device is designed for generation of high spectral efficiency optical modulation formats. We demonstrate generation of 21.4 Gb/s quadrature phase shift keyed optical signals with electrical data drives of 2V(pp) amplitudes, achieving a bit error rate of 10(-9) with the required optical signal to noise ratio of ~18 dB in a 0.1 nm resolution bandwidth.