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In this paper, we study the use of silicon microring modulators in an integrated mode-division multiplexing (MDM) network for short-reach interconnects using discrete multitone (DMT) modulation. A fiber grating coupler array is used as a high-speed optical interface between the on-chip mode channels and off-chip multicore fiber (MCF). The whole link has a crosstalk level lower than -23.1 dB. The MDM network can work without the crosstalk compensation of digital signal processing. We present experimental results of the linearity of the silicon microring modulator in terms of spurious-free dynamic range (SFDR). The third order intermodulation distortion SFDR is 93.4 dB/Hz2/3 at 20 GHz. We can improve system performance by using adaptive nonlinear equalizer at the DMT receiver to mitigate transmitter and transmission impairments. An aggregate bitrate above 312 Gb/s is achieved with a bit error ratio of 3.8 X 10−3. With the addition of nonlinear equalizer, the line rates of the MDM network can be further increased to about 330 Gb/s. The experimental results demonstrate the feasibility of single wavelength DMT transmission in MDM network with MCF. [ABSTRACT FROM AUTHOR]

We propose to use backward Raman amplification to mitigate the crosstalk in multichannel optical parametric sampling. The performances of multichannel sampling based on four-wave mixing (FWM) have been experimentally compared with different Raman pump powers. Optical crosstalk is suppressed by lowering the input signal power so that the depletion of the parametric pump and higher order FWM products are reduced. Meanwhile, Raman amplification compensates the parametric pump power and improves the conversion efficiency, thus maintaining the output idler power. A 12.2- and 13.6-dB reduction of crosstalk-induced frequency components has been achieved in two output channels. We also analyze bandwidth broadening resulting from the self-phase modulation of the pulsed parametric pump for the two cases when it is amplified by an erbium-doped fiber amplifier and by the Raman pump. [ABSTRACT FROM PUBLISHER]

We present a novel reconfigurable optical add-drop filter based on phase-sensitive amplifiers (PSAs). By manipulating the relative phase among an optical pump, signals, and idlers, spectral selectivity can be achieved along with low noise amplification. The use of backward Raman amplification enhances the phase-sensitive operation of the parametric process, enabling higher stopband isolation and lower intra-band crosstalk. A Raman-assisted phase-sensitive amplifier (RA-PSA) is characterized in detail, showing a 7.8-dB combined gain extinction ratio enhancement and 10.85-dB gain improvement. For the first time, we demonstrate an RA-PSA enabled optical add-drop filter with less than 0.4-dB penalty using three-channel QPSK signals. The novel scheme provides a simple way to enhance the extinction ratio of the PSA enabled add-drop filter, which can be an essential subsystem in optical links based on phase-sensitive amplification. [ABSTRACT FROM PUBLISHER]