Ultrahigh Capacity Fiber-Optic Transmission Systems

The subject of this thesis is ultrahigh capacity optical communication systems. Such systems will use a combination of techniques for dense wavelength-division multiplexing (D-WDM) and ultrahigh speed all-optical time-division multiplexing (O-TDM). The work may be separated into two parts; the first part aims at ultrahigh bit-rate applications involving clock-recovery and high speed O-TDM field transmission experiments. Two single channel field experiments with line rates of 40 and 80 Gbit/s over 400 and 172 km respectively are demonstrated using soliton pulses environment. The reported line rate of 80 Gbit/s was the first single channel transmission experiment above 40 Gbit/s over installed fiber. Furthermore, nonlinear crosstalk due to four-wave mixing in D-WDM systems are studied under the influence of PMD. The second part deals with a novel type of amplifiers based on fiber optical parametric amplification. One important feature of these amplifiers is that they may be tailored to operate at a specific wavelength and they may thus open up new, previously unused, transmission bands. A cw pumped fiber based parametric amplifier is demonstrated with 39 dB black box gain. This is the first demonstration of a cw pumped fiber based parametric amplifier showing a net black box gain. The very fast relaxation time (~fs) may be used for all-optical signal processing. Three signal processing applications based on a fiber optical parametric amplifier are proposed and demonstrated; a 40-10 Gbit/s O-TDM demultiplexer with more than 40 dB gain, a 40 GHz pulse source providing wavelength tunable pulses below 4 ps and an all-optical sampling system with a temporal resolution of 1.6 ps demonstrating visualization of 300 Gbit/s data. Finally, a simple technique for increasing the maximum launched power into an optical fiber by increasing the stimulated Brillouin scattering threshold is proposed and evaluated

Ultrahigh Capacity Fiber-Optic Transmission Systems

The subject of this thesis is ultrahigh capacity optical communication systems. Such systems will use a combination of techniques for dense wavelength-division multiplexing (D-WDM) and ultrahigh speed all-optical time-division multiplexing (O-TDM). The work may be separated into two parts; the first part aims at ultrahigh bit-rate applications involving clock-recovery and high speed O-TDM field transmission experiments. Two single channel field experiments with line rates of 40 and 80 Gbit/s over 400 and 172 km respectively are demonstrated using soliton pulses environment. The reported line rate of 80 Gbit/s was the first single channel transmission experiment above 40 Gbit/s over installed fiber. Furthermore, nonlinear crosstalk due to four-wave mixing in D-WDM systems are studied under the influence of PMD. The second part deals with a novel type of amplifiers based on fiber optical parametric amplification. One important feature of these amplifiers is that they may be tailored to operate at a specific wavelength and they may thus open up new, previously unused, transmission bands. A cw pumped fiber based parametric amplifier is demonstrated with 39 dB black box gain. This is the first demonstration of a cw pumped fiber based parametric amplifier showing a net black box gain. The very fast relaxation time (~fs) may be used for all-optical signal processing. Three signal processing applications based on a fiber optical parametric amplifier are proposed and demonstrated; a 40-10 Gbit/s O-TDM demultiplexer with more than 40 dB gain, a 40 GHz pulse source providing wavelength tunable pulses below 4 ps and an all-optical sampling system with a temporal resolution of 1.6 ps demonstrating visualization of 300 Gbit/s data. Finally, a simple technique for increasing the maximum launched power into an optical fiber by increasing the stimulated Brillouin scattering threshold is proposed and evaluated

Backhaul evolution

Microwave backhaul technology plays a significant role in providing reliable mobile network performance and is well prepared to support both the evolution of LTE and the introduction of 5G. Work has now started on the longer-term use of frequencies beyond 100GHz, targeting the support of 5G evolution toward 2030