Benny Mikkelsen

Pseudo-Linear Transmission of High-Speed TDM Signals: 40 and 160 Gb/s

Publisher Summary The pseudo–linear transmission is a method for the transmission of high-speed time-division multiplexed (TDM) signals where fast variations of each channel waveform with cumulative dispersion allows important averaging of the intrachannel effects of fiber nonlinearity. The pseudo–linear transmission involves complex optimization of modulation format, dispersion mapping, and nonlinearity. These transmissions occupy a space somewhere between dispersion-mapped linear transmission and nonlinear soliton transmission. The pseudo-linear regime of transmission is characterized by a rapid pulse broadening, which results in a dramatic reduction of the solitonic effect on each pulse. As a result, full dispersion compensation can be used in this regime. Extensive analysis of pseudo-linear transmission and reviews of the TDM transmission experiments at 40 and 160 Gb/s have been provided in the chapter. Two new forms of nonlinear interactions between rapidly dispersing pulses namely intrachannel cross–phase modulation (IXPM) and intrachannel four–wave mixing (IFWM) are also presented. These two intrachannel effects are the most important nonlinear interactions in pseudo-linear transmission and determine the dispersion mapping even for the wavelength–division multiplexed (WDM) systems. Further, the chapter describes the semiconductor–based technologies that enable the development of stable and reliable high–speed transmitters and receivers.Publisher Summary The pseudo–linear transmission is a method for the transmission of high-speed time-division multiplexed (TDM) signals where fast variations of each channel waveform with cumulative dispersion allows important averaging of the intrachannel effects of fiber nonlinearity. The pseudo–linear transmission involves complex optimization of modulation format, dispersion mapping, and nonlinearity. These transmissions occupy a space somewhere between dispersion-mapped linear transmission and nonlinear soliton transmission. The pseudo-linear regime of transmission is characterized by a rapid pulse broadening, which results in a dramatic reduction of the solitonic effect on each pulse. As a result, full dispersion compensation can be used in this regime. Extensive analysis of pseudo-linear transmission and reviews of the TDM transmission experiments at 40 and 160 Gb/s have been provided in the chapter. Two new forms of nonlinear interactions between rapidly dispersing pulses namely intrachannel cross–phase modulation (IXPM) and intrachannel four–wave mixing (IFWM) are also presented. These two intrachannel effects are the most important nonlinear interactions in pseudo-linear transmission and determine the dispersion mapping even for the wavelength–division multiplexed (WDM) systems. Further, the chapter describes the semiconductor–based technologies that enable the development of stable and reliable high–speed transmitters and receivers.

Optoelectronic phase-locked loop with balanced photodetection for clock recovery in high-speed optical time-division-multiplexed systems

An optoelectronic phase-locked loop (PLL) for clock recovery in high-speed optical time-division-multiplexed (OTDM) systems is proposed and experimentally demonstrated. The proposed scheme incorporates a pair of balanced photodetector through which the polarity ambiguity in error signal is resolved, and the cancellation of laser noise enables clock recovery with low timing jitter. Using an electroabsorption modulator as a phase detector, a 10-GHz clock signal with root-mean-square (rms) timing jitter of 300 fs is successfully extracted from 40 and 80 Gb/s return-to-zero (RZ) data stream. A 40- to 10-Gb/s demultiplexing is performed by using the recovered clock signal with no penalty introduced in the bit error rate performance.

Chapter 6 – Pseudo-Linear Transmission of High-Speed TDM Signals: 40 and 160 Gb/s

Publisher Summary The pseudo–linear transmission is a method for the transmission of high-speed time-division multiplexed (TDM) signals where fast variations of each channel waveform with cumulative dispersion allows important averaging of the intrachannel effects of fiber nonlinearity. The pseudo–linear transmission involves complex optimization of modulation format, dispersion mapping, and nonlinearity. These transmissions occupy a space somewhere between dispersion-mapped linear transmission and nonlinear soliton transmission. The pseudo-linear regime of transmission is characterized by a rapid pulse broadening, which results in a dramatic reduction of the solitonic effect on each pulse. As a result, full dispersion compensation can be used in this regime. Extensive analysis of pseudo-linear transmission and reviews of the TDM transmission experiments at 40 and 160 Gb/s have been provided in the chapter. Two new forms of nonlinear interactions between rapidly dispersing pulses namely intrachannel cross–phase modulation (IXPM) and intrachannel four–wave mixing (IFWM) are also presented. These two intrachannel effects are the most important nonlinear interactions in pseudo-linear transmission and determine the dispersion mapping even for the wavelength–division multiplexed (WDM) systems. Further, the chapter describes the semiconductor–based technologies that enable the development of stable and reliable high–speed transmitters and receivers.Publisher Summary The pseudo–linear transmission is a method for the transmission of high-speed time-division multiplexed (TDM) signals where fast variations of each channel waveform with cumulative dispersion allows important averaging of the intrachannel effects of fiber nonlinearity. The pseudo–linear transmission involves complex optimization of modulation format, dispersion mapping, and nonlinearity. These transmissions occupy a space somewhere between dispersion-mapped linear transmission and nonlinear soliton transmission. The pseudo-linear regime of transmission is characterized by a rapid pulse broadening, which results in a dramatic reduction of the solitonic effect on each pulse. As a result, full dispersion compensation can be used in this regime. Extensive analysis of pseudo-linear transmission and reviews of the TDM transmission experiments at 40 and 160 Gb/s have been provided in the chapter. Two new forms of nonlinear interactions between rapidly dispersing pulses namely intrachannel cross–phase modulation (IXPM) and intrachannel four–wave mixing (IFWM) are also presented. These two intrachannel effects are the most important nonlinear interactions in pseudo-linear transmission and determine the dispersion mapping even for the wavelength–division multiplexed (WDM) systems. Further, the chapter describes the semiconductor–based technologies that enable the development of stable and reliable high–speed transmitters and receivers.

160-Gb/s free-space transmission link

12 We demonstrate record error-free transmission of a single 160 Gb/s RZ data channel at 1550 nm over 200 meters of free space. This represents the largest data bandwidth transmitted over this distance, without the use of optical fibers.

A 160 Gb/s free space transmission link

In situations where fiber installation is complex/costly, or in applications requiring quick installation or temporary connectivity, a multi-gigabil wireless solution would be an attractive compliment to fiber-line systems. RF microwave technologies have not been keeping up with the bandwidth capacity of fiber systems. On the other hand, optical wireless systems have recently been demonstrated to provide multi-gigabit connectivity, without frequency spectrum licensing issues (as in RF microwave) or digging rights-of-way. [1]

Parametric wavelength conversion and phase conjugation in LiNbO/sub 3/ waveguides

Recently, we have shown that using a cascaded /spl chi//sup (2)/ process in optimized periodically-poled LiNbO/sub 3/ (PPLN) waveguides, one can achieve high efficiency wavelength conversion (better than -10 dB fiber to fiber) while preserving all the advantages of parametric processes. In addition this parametric wavelength conversion is accompanied by phase conjugation. The results shown in this paper add another attractive feature of parametric LiNbO/sub 3/ wavelength converters, namely, their successful performance at data rates as high as 160 Gb/s. Their parametric nature make these devices suitable for even higher line rates.

High speed clock recovery using an optoelectronic phase locked loop implemented with balanced photodetection

We have proposed and experimentally demonstrate high-speed clock recovery by employing a novel optoelectronic phase-locked loop. The DC ambiguity caused by the use of optoelectronic phase detector is resolved by balanced photodetection. Low timing jitter of the recovered clock indicates a potential for operation beyond 100 Gb/s using this scheme.