We introduce a traffic model for circuit switched all-optical networks (AONs) which we then use to calculate the blocking probability along a path for networks with and without wavelength changers. We investigate the effects of path length, switch size, and interference length (the expected number of hops shared by two sessions which share at least one hop) on blocking probability and the ability of wavelength changers to improve performance. Our model correctly predicts unobvious qualitative behavior demonstrated in simulations by other authors.

Models of blocking probability in all-optical networks with and without wavelength changers

Semiconductor optical amplifiers are useful building blocks for all-optical gates as wavelength converters and OTDM demultiplexers. The paper reviews the progress from simple gates using cross-gain modulation and four-wave mixing to the integrated interferometric gates using cross-phase modulation. These gates are very efficient for high-speed signal processing and open up interesting new areas, such as all-optical regeneration and high-speed all-optical logic functions.

/pdf/semiconductor-optical-amplifier-based-all-optical-gates-for-4wdu6yc0vj.pdf

Semiconductor optical amplifier-based all-optical gates for high-speed optical processing

Since the first deployments of fiber-optic com- munication systems three decades ago, the capacity carried by a single-mode optical fiber has increased by a staggering 10 000 times. Most of the growth occurred in the first two decades with growth slowing to ten times in the last decade. Over the same three decades, network traffic has increased by a much smaller factor of 100, but with most of the growth occurring in the last few years, when data started dominating network traffic. At the current growth rate, the next factor of 100 in network traffic growth will occur within a decade. The large difference in growth rates between the delivered fiber capacity and the traffic demand is expected to create a capacity shortage within a decade. The first part of the paper recounts the history of traffic and capacity growth and extrapolations for the future. The second part looks into the technological chal- lenges of growing the capacity of single-mode fibers by pre- senting a capacity limit estimate of standard and advanced single-mode optical fibers. The third part presents elementary capacity considerations for transmission over multiple trans- mission modes and how it compares to a single-mode trans- mission. Finally, the last part of the paper discusses fibers supporting multiple spatial modes, including multimode and multicore fibers, and the role of digital processing techniques. Spatial multiplexing in fibers is expected to enable system capacity growth to match traffic growth in the next decades.

https://www.icg.isy.liu.se/courses/optical/Capacity_Trends.pdf

Capacity Trends and Limits of Optical Communication Networks Discussed in this paper are: optical communication network traffic evolution trends, required capacity and challenges to reaching it, and basic limits to capacity.

Since the first deployments of fiber-optic communication systems three decades ago, the capacity carried by a single-mode optical fiber has increased by a staggering 10 000 times. Most of the growth occurred in the first two decades with growth slowing to ten times in the last decade. Over the same three decades, network traffic has increased by a much smaller factor of 100, but with most of the growth occurring in the last few years, when data started dominating network traffic. At the current growth rate, the next factor of 100 in network traffic growth will occur within a decade. The large difference in growth rates between the delivered fiber capacity and the traffic demand is expected to create a capacity shortage within a decade. The first part of the paper recounts the history of traffic and capacity growth and extrapolations for the future. The second part looks into the technological challenges of growing the capacity of single-mode fibers by presenting a capacity limit estimate of standard and advanced single-mode optical fibers. The third part presents elementary capacity considerations for transmission over multiple transmission modes and how it compares to a single-mode transmission. Finally, the last part of the paper discusses fibers supporting multiple spatial modes, including multimode and multicore fibers, and the role of digital processing techniques. Spatial multiplexing in fibers is expected to enable system capacity growth to match traffic growth in the next decades.

Capacity Trends and Limits of Optical Communication Networks

A single wavelength channel, optical time division multiplexed and polarisation multiplexed 128 Tbit/s signal has been successfully transmitted over 70 km Third- and fourth-order simultaneous dispersion compensation was used with a 10 GHz synchronous phase modulator The input pulse width was 380 fs, and the transmitted pulsewidth was 400 fs All 128 channels demultiplexed to 10 Gbit/s had a bit error rate of less than 1/spl times/10/sup -9/

1.28 Tbit/s-70 km OTDM transmission using third- and fourth-order simultaneous dispersion compensation with a phase modulator

100 Gbit/s/spl times/10 channel (1 Tbit/s) optical signals from a single supercontinuum WDM source are successfully transmitted over a 40 km dispersion-shifted fibre using a 400 GHz channel-spaced arrayed-waveguide grating WDM MUX/DEMUX as well as a 100 Gbit/s-10 Gbit/s all-optical TDM MUX/DEMUX.

1 Tbit/s (100 Gbit/s × 10 channel) OTDM/WDM transmission using a single supercontinuum WDM source

Single channel 400 Gbit/s time-division multiplexed optical transmission is successfully demonstrated using 0.98 ps transform-limited optical pulses over 40 km. The dispersion slope of the transmission fibre is compensated to suppress the distortion of the signal pulses.

Single channel 400 Gbit/s time-division-multiplexed transmission of 0.98 ps pulses over 40 km employing dispersion slope compensation

A single channel, single polarisation 200 Gbit/s time-division-multiplexed optical transmission experiment is successfully demonstrated using optical short pulses generated by supercontinuum. A prescaled clock is recovered directly from the 200 Gbit/s signal to drive an all-optical demultiplexer.

200 Gbit/s, 100 km time-division-multiplexed optical transmission using supercontinuum pulses with prescaled PLL timing extraction and all-optical demultiplexing

Successful 50 GHz operation of a phaselocked loop is demonstrated using four-wave mixing in a travelling-wave laser diode optical amplifier. A prescaled 6.3 GHz clock is recovered from a 50 Gbit/s TDM optical signal using the 50 GHz phase comparison output obtained as the crosscorrelation between a 50 Gbit/s optical signal and a short ( >

Prescaled 6.3 GHz clock recovery from 50 Gbit/s TDM optical signal with 50 GHz PLL using four-wave mixing in a travelling-wave laser diode optical amplifier

100 Gbit/s all-optical demultiplexing is successfully demonstrated using optical four-wave mixing in a travelling wave laser diode amplifier. A demultiplexed 6.3 Gbit/s signal shows only 5 dB power penalty from the baseline.

O. Kamatani

Papers

1 Tbit/s (100 Gbit/s × 10 channel) OTDM/WDM transmission using a single supercontinuum WDM source

Single channel 400 Gbit/s time-division-multiplexed transmission of 0.98 ps pulses over 40 km employing dispersion slope compensation

200 Gbit/s, 100 km time-division-multiplexed optical transmission using supercontinuum pulses with prescaled PLL timing extraction and all-optical demultiplexing

Prescaled 6.3 GHz clock recovery from 50 Gbit/s TDM optical signal with 50 GHz PLL using four-wave mixing in a travelling-wave laser diode optical amplifier

100 Gbit/s all-optical demultiplexing using four-wave mixing in a travelling wave laser diode amplifier