Video: Finisar WSS Flexgrid Technology Demo at OFC 2011

ECOC Tradeshow Recap and the Importance of Flexgrid™

Just got back from the ECOC tradeshow, or as I joked at our customer event on Tuesday night, the ECDC trade show – “European Colorless Directionless Contentionless” Conference.

Despite losing my suitcase and having to rush-out to buy some of the latest Italian fashions (can you say slim fit?), it was a good industry show.

Finisar was no stranger to the ROADM architecture theme with our new Flexgrid™ technology demo. Flexgrid is a WSS software feature we believe will be critically important to carriers in their deployments of ROADMs in the future.

As described in our recent press release, Flexgrid™ WSS technology enables dynamic control of channel center frequency and channel bandwidth within a WSS, from 50 GHz to 200 GHz in 12.5 GHz steps, with no penalty on any aspect of WSS performance. Flexgrid™ draws upon the inherent flexibility and performance of Finisar’s Liquid Crystal on Silicon (LCoS) optical engine which we believe will address carrier demands for flexible bandwidth-capable ROADMs in next-generation networks. LCoS technology enables a WSS to be very flexible with many features including the ability to optimize (or contour) the channel shape of each individual wavelength and provide configurable dispersion compensation for best transmission performance.

Flexgrid becomes very interesting when one looks to the next Ethernet data rate as the following example shows.

If you assume the next data rate beyond 100G will be 400G, then:

Obviously 400G will require an advanced modulation format, so if you assume:
• Modulators and electronics are limited to 30G symbols/s
• 16 QAM give 4 bits/symbol
• Two polarizations x two wavelengths gives another factor of four
• FEC takes away 20%
• 30x4x2x2= 480Gb/s. Take away 20% = 400Gb/s Ethernet

Based on this 16-QAM, 30GHz, dual polarization modulation format:
• 60GHz is needed for the signal
• Add 10GHz channel boundaries on each side of the signal
• Allow 3-5GHz between signals (including laser drift)

This means the bandwidth required to transport a 400GE signal is somewhere around 85GHz.
One way to transport this would be to use a 100GHz grid since 85GHz would fit within the 100GHz channel. However, moving to 100GHz channel spacing to accommodate the 400G channel means that the carrying efficiency of the fibre actually drops for other (lower bandwidth) signals which would normally be carried on 50GHz channels. Since signal heterogeneity is likely to be a feature of future networks, and carriers are looking to maximize fiber carrying capacity (and hence minimize cost/Mbit/km), then it is clearly not an option to just return to a 100GHz grid.

Furthermore, the actives associated with transporting 400GE (say using a 16-QAM dual polarization modulation format) are likely to be expensive. Thus, we will spend a very significant amount on optics to increase the throughput on a given fiber in a way in which spectral bandwidth is not optimized. However, if a network operator has already deployed a ROADM using Flexgrid™ technology, they could preset that specific wavelength to 87.5GHz granularity using a very simple software command. Voila, you have a spectrally efficient 400GE wavelength that increases the spectral efficiency of fiber by a factor of 2.3 (130% increase as opposed to 100% increase using 100 GHz channels) as well as providing efficient bandwidth allocation for other types of traffic and hence maximizing the carrying capacity of a given fibre route. This should ultimately also make the cost associated with upgrading to 400GE significantly less expensive for a carrier.

People ask why should we worry about deploying ROADMs for 400GE? As an industry, we are just starting to deliver 100GE. Well, as Glenn Wellbrock at Verizon stated “we like to deploy our ROADM equipment for 10 years”. If you assume that 400GE will likely start to ship in the next 5 years (pretty likely considering that the standard efforts for 100GE started in 2006 and now 4 years later, we are shipping 100GE), then not deploying Flexgrid would be very short-sighted. It would mean that in 5 years time, a carrier would have to rip out old ROADMs to support 400GE – a very expensive proposition.

Any comments are welcome!

Finisar Australia Expands to Support Growing WSS ROADM Market

Last month, Finisar Australia unveiled a new office at its South Sydney headquarters, located in Waterloo, NSW. This newly expanded space will support the R&D efforts necessary to meet the growing market demand for our WSS ROADM products.

The Finisar AU staff was especially excited to have Premier of NSW Kristina Keneally on-site for a ribbon-cutting ceremony. Ms. Keneally was able to observe first-hand the expanding operations, including state-of-the art research and development laboratories, manufacturing, and office space which will house a growing Finisar staff.

This new office comes at a significant time in our international growth, specifically in support of telecom service providers who are looking for greater flexibility as they design their networks. International market research firm, Infonetics Research, predicts that the ROADM optical equipment market will continue to be the fastest growing segment of the optical equipment business, and the key component fueling this is the WSS or Wavelength Selective Switch. Finisar is sufficiently positioned and well prepared to accommodate this market surge and we look forward to further building this team to support our customers.

We are actively recruiting talented people to support our operations in Australia. If you are interested, please e-mail your CV/Resume to HR@finisar.com or call +1-408-542-4128.

Premier of NSW Kristina Keneally visits Finisar Australia to conduct a ribbon cutting ceremony of its newly expanded office with Andrew Bartos (August 2010)

Premier of NSW Kristina Keneally visits Finisar Australia laboratory (August 2010)

Future Proof Your Network: Flexible Grid Architecture

The driver for any development in optical communications technology is, almost without exception, a reduction in cost-per-bit/km travelled (although there’s one interesting exception to this which I’ll talk about at some future point). This intensely capitalistic and utilitarian approach has enabled the dramatic growth in the internet (YouTube needs very low cost/bit to be viable), but are we approaching the point where the rate of cost reduction may start to slow down? In the US, for example, there’s recently been a move away from ‘all you can eat’ data plans to something approaching (very slowly) the capped plans found in many other parts of the world – partially in response to the recognition that there is a finite amount of bandwidth available at any point in the network.

In the optical space, we have, over the past 15 years, moved to higher and higher per-channel bit rates running on more-closely-spaced WDM channels. However, we are (as I mentioned previously) reaching the limit of what can be achieved on the ITU Grid-based systems introduced in the 1990s. Consequently, fibre bandwidth, which only a few years ago was being proselytised by Gilder as being effectively ‘infinite’, is increasingly being seen as a finite resource which needs to be managed as effectively as possible using all the techniques at our disposal.

One solution, which is gaining a great deal of traction at the moment is to move away from the constraints of the ITU Grid to what we term a flexible grid architecture where the channel optical bandwidth can be dynamically adjusted to meet the requirements of the signal being sent through it and hence maximise the data carrying capacity of the fibre.

This ability to control the channel bandwidth and position with GHz resolution has been utilized in many research papers as I discussed in my previous blog. In practice, however, the complexity of managing a network with such fine granularity may outweigh its advantages. Market requirements indicate that a channel bandwidth granularity of 12.5 GHz will meet future channel bandwidth requirements and that even 25 GHz channel bandwidth increments may be sufficient.

First generation WSS (typically based on MEMS and/or Liquid Crystal technologies) allocate a single switching element (pixel) to each channel which means that the channel bandwidth and centre frequency are fixed at the time of manufacture and cannot be changed in service. However, second generation WSS, based on Liquid Crystal on Silicon (LCoS) or 2D MEMS mega-pixel matrix switching arrays, permit dynamic control of channel centre frequency and bandwidth through ‘on the fly’ modification of internal pixel arrays via embedded software.

Furthermore, not only must the core switching elements in a ROADM be capable of supporting flexible grid architectures, but the multiplexer/demultiplexers and filter arrays must support the same degree of flexibility. The flexibility provided by LCoS technology can also be applied to these high-port-count (e.g. 1×23) multiplexer/demultiplexers and programmable filter arrays.

This discussion has focused on the requirements for the wavelength-selective elements in a flexible-grid ROADM as these will be the first part of the flexible grid network that has to be deployed to ensure the network is future-proofed. However flexible grid networks will also require additional component developments including scanning optical channel monitors capable of handling polarization multiplexed signals with varying bandwidths and signal formats and signal (and local oscillator, for coherent systems) lasers capable of operating at the finer frequency increments implied by flexible grid architectures (6.25 GHz for 12.5 GHz channel increments and 12.5 GHz for 25 GHz channel increments). This provides a continuing challenge to those of us in the optical space as we continue to improve the price/performance of our components and modules which underpin the networks of the future.

Flexible grid technology (not grid-less) will allow the optimum usage of the finite operating window in a fibre and allow operators to continue down the path of reducing the cost per bit/km of data travelling through the network.

Any comments are welcome.

Finisar Innovation Heroes!

Simon Poole and Steve Frisken, the founders of Finisar Australia have been recognised for their contributions to Australian Innovation by being named as two of the Warren Centre’s “Innovation Heroes” for 2010 at a ceremony at the Powerhouse Museum in Sydney on Tuesday evening, 8th June.

The Innovation Heroes awards are presented to individuals recognised for developing and commercialising a range of cutting-edge technologies and innovations that have significantly contributed to the economic progress of Australia.

According to Professor Mike Dureau, Executive Director of The Warren Centre, “It’s one thing to have a good engineering idea and another to develop and commercialise the technology and then sell it to the world. Each of this year’s Heroes Award recipients possess a unique vision and drive to see their products commercialised to benefit of a range of local and international industries. The capacity of each finalist to successfully give life to great ideas that also benefit the Australian economy must be applauded.”

“Australian engineers are a leading force in the economic growth of Australia and their creativity, innovation and entrepreneurial skills are the qualities that continue to help shape the future of Australia and in many cases, the world,” added Professor Dureau.

The citations for Simon and Steve were as follows:

Dr. Simon Poole is an innovator in communications and photonics technologies. He co-invented the Erbium-Doped Fibre Amplifier with a market of $300M pa. He founded and sold two successful photonics companies, INDX and Engana, responsible for developing world leading Wavelength Selective Switching technologies. He is now working as the Director, New Business Ventures of Finisar Australia to expand the company’s core activities into the field of Optical Instrumentation.

Dr. Steven Frisken was a co-founder of Photonic Technologies which was acquired by Nortel Networks, and he became the interim CEO. He introduced a telecommunications optical circulator adopted by industry and passive and dynamic EDFA gain flattening filters leading to the first laboratory DWDM amplifiers. Steve Frisken also co-founded Engana with Simon Poole, Australia’s most successful optical start-up company.

Congratulations Simon and Steve!