Finisar Australia Wins Prestigious Engineering Award

This week’s post comes from guest blogger, Dr. Simon Poole.

Us Australians are well known for being quiet, shy, retiring types, so it was great to get a chance to celebrate when Finisar Australia won the prestigious Bradfield Award at the Engineering Excellence Awards held in Sydney last month. The J.J.C. Bradfield Award is presented to the overall winner of Sydney Division of Engineers Australia Excellence Awards. It recognises an accomplishment of exceptional engineering merit and was presented to Finisar for the development of the Flexgrid™ capability for the DWP family of Wavelength Selective Switches.

Finisar’s FlexGrid™ is a flexible software enhancement within the company’s range of Wavelength Selective Switches (WSS) which allows telecommunications carriers to re-route signals throughout their network.

“A FlexGrid WSS can be used for instance if someone digs up a cable by accident. The telecommunication provider can use it to re-route traffic of phone and internet so phones don’t drop out. It can also be used on occasions like Mother’s Day when capacity goes up – carriers can use the Flexgrid to add more capacity to their network,” says Dr Steve Winnall, Director of Product Engineering at Finisar Australia.

“There are problems with the current legacy system which telecommunication provider now use. For example, in situations like the City-to-Surf (a major fun-run in Sydney attracting over 35,000 competitors) people couldn’t make a mobile call because there were so many people in one location. Our product helps to alleviate that and provide a better quality of service. This is a great success story in terms of manufacturing and innovation in Australia as 99 per cent of our sales have been through export, so it is a device that is being used all over the world.”

The judges said the Flexgrid is an innovation that “overcomes the current constraint associated with fixed channel plans used in current optical networks. It is a unique and world leading product in optical fibre telecommunications.

Finisar also won two other categories for its WaveShaper and DWP products and the Flexgrid product was also highly commended in the Innovations and inventions category.

The black-tie presentation dinner was attended by 10 Finisar employees who are pictured with the award below.

All three Finisar winners on the night now advance to the national finals to be held in Canberra in November.

Flexgrid ROADM update

I’ve blogged in the past about the expected demand for Flexgrid-based transmission systems to accommodate future high-bandwidth signals and, at OFC earlier this month this was again a very hot topic, with numerous workshops and technical sessions covering both component and systems aspects of Flexgrid networks. I was a speaker at a workshop on “Spectrally Flexible Optical Networks” organised by BT and ALU and a straw poll at the end of the workshop indicated that of the approximately 100+ attendees at this particular workshop, well over 95% thought that Flexgrid networks were the way of the future. (A personal plea to future OFC Workshop Organisers: 8am is a ridiculously early start time for a Monday workshop, particularly when you’ve just flown in from Asia/Australia as two of the panel had – it was the equivalent of 3am for us!)

One area of discussion was the need to trade off network OSS complexity against providing full (to the GHz level) flexibility in Flexgrid channel bandwidth and centre frequency allocation. It was clear, as discussed previously, that providing control to the GHz level would be unusable but there was a strong preference from at least two of the major carriers for the minimum bandwidth ‘slice’ to be 12.5GHz to support the existing ITU grid down to 25GHz channel spacing. How this works can be seen in the diagram below which shows how 12.5GHz slices can be used to build up both standard ITU-GRID channels as well as arbitrary Flexgrid channels.

From a Finisar perspective we announced at OFC that we’re now shipping fully Flexgrid-enabled WSS with 12.5GHz channel spacing to allow alignment with ITU G.694.1 channel allocation right down to the 25 GHz channel spacing. This is allowing our customers to demonstrate Flexgrid networking and develop the associated network hardware and control software needed to support Flexgrid implementation.

Whilst Flexgrid WSS are the critical component for future Flexgrid networks, a full Flexgrid component ecosystem is required to support the WSS and it was pleasing to see the first Flexgrid-compatible Optical Channel Monitors (OCMs) being talked about by a couple of vendors at the OFC trade show. The issue of the overall Flexgrid ecosystem is an important one which I’ll return to in a future post.

A Yuletide Request from Optics Researchers: All I want for Christmas is…

As the festive season drags us kicking and screaming into rounds of seasonal silliness (and if you’ve never seen a man in a false beard and Santa Suit surrounded by fake snow in 40 degree heat (100F for the renegade non-metrics out there) you haven’t lived) it’s time to hope you’ve been a good person and send that letter to the North Pole and hope that the man in red can make it through the air conditioning vents and deliver something for all those of us who work at the optical layer. I’m therefore making three Christmas wishes for developments from our researchers worldwide.

Better fibres, please.

Silica is a wonderful material and we all love it dearly for its incredible transparency, strength and (now we know how to do it) ease of processing. However, it still isn’t ideal. It does have some loss and, possibly even worse, has a level of non-linearity. The combination of the two means that we still don’t have the perfect transmission medium. So my first Christmas wish is for a fibre which has zero loss and no non-linearity. Maybe some of the hollow-core Photonic Crystal Fibre designs that have been proposed will get us there in the end, but I haven’t seen any signs of real progress towards practical, manufacturable designs which could be useful in a real-world transmission system. Since we will therefore always have some form of loss, this leads to my second wish…

More Gain.

Since we don’t have zero loss fibres, we need optical amplifiers. As an industry, we have been incredibly fortunate that the EDFA gain region and the minimum loss window of silica coincide so well. This has supported the development of DWDM systems in all their shapes and sizes over the past 25 years. However, as we keep pushing system capacity, we’re running out of gain in the EDFA (even allowing for L-band) and having to drag Raman amplifiers kicking and screaming into the mainstream of technology. However, Raman amplification has its own issues (particularly noise figure) and what we’d really like is an amplifier with 0dB noise figure, 30+ dB of gain, saturated output powers of >+20dBm and operating over a 200nm bandwidth. Phase Sensitive Amplifiers show some promise here, although the technology is still very immature and is unproven at a network level.

Polarisation be gone.

With the imminent introduction of coherent transmission systems, Polarisation Mode Dispersion (PMD) will no longer be the bugbear it was for high-speed 40G systems. However, our old friend PDL (Polarisation Dependent Loss) now becomes a limiting factor, so my final wish is for optical components with no PDL (or Polarisation Dependent Gain – PDG).

I am sure there are other things we could wish for– let me know your thoughts and suggestions.

In the meantime, have a cool yule and a restive festive.

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 Australia, oh so nice!

As you may have read recently, Finisar is now the number 1 WSS/ROADM supplier globally, with a particular strength in high-performance WSS for 50GHz channel spacing. As I discussed in my last post the flexibility of our core LCoS technology means that we’re extremely well positioned to meet the needs of upcoming flex-grid architectures for 100G and above transmission. Our WaveShaper product range is also expanding – again driven strongly by the growth in advanced modulation formats and coherent systems but also by expansion into other markets including microwave photonics and laser pulse manipulation.

To support all this growth, we’re expanding our engineering and R&D teams here in Sydney and are looking to hire a whole lot more engineers and scientists. We’re looking for people with a range of skills, including opto-mechanical engineers, software engineers, optical designers and high-speed electronics whizzes as well as manufacturing and process engineers to support the manufacturing ramp that comes with a growing market share in a rapidly-expanding market.

Sydney is a tremendously cosmopolitan city (heck, we’ve even got Lou Reed and Laurie Anderson curating a city-wide arts festival this month) with a great, year-round lifestyle and (particularly important for me these days) great food and wine…

Our facility is located in Waterloo, only 10 minutes to the heart of the city, with thriving local arts and restaurant scene and good access by road and public transport. We provide competitive salaries and full relocation packages. If you’re interested, check out this page or contact theodora.liosatis@finisar.com.