OFC 2011

Optical Fibre Communications (OFC) is the world’s largest technical conference and trade show in fibre optics. A number of years ago it merged with what had previously been the National Fibre Optics Engineers Conference (NFOEC) and so it is still officially referred to as OFC/NFOEC. This year the show was held in downtown Los Angeles at the Convention Centre. A large area next to the convention centre has been re-developed to provide a large complex of restaurants and bars (and a basketball stadium). This was where we had a get together for CFCEs and CONEs.
The trade show this year was about 20% bigger than last year and the conference was well attended by an international audience. It seemed that there were more technical presentations than ever before, often with 10 parallel streams! Some recurrent themes in the technical sessions included:

• what comes after 100G?
• will DWDM systems break out of the rigid ITU grid?
• will we need Gridless ROADM architectures?
• measurement of complex signal modulation formats

Followers of this blog may recall the three ’M’ technologies to achieve higher throughput per fibre:

• multi-level modulation formats
• multi-core fibre
• multimode fibres using mode division multiplexing

It was interesting to hear about the progress that had been made with these in the Post Deadline Papers where the very latest developments are showcased.
Alcatel Lucent reported 64-QAM transmission over 4x100km spans of fibre.
Two companies presented transmission experiments based on 7-core fibre. In one of these a total of 109Tb/s were sent over 16.8km of fibre. Each of the seven cores carried 97 DWDM channels in each of two polarisation states, each channel carried 86Gb/s using QPSK modulation. Each core had a refractive index ‘trench’ around it – just like bend-tolerant singlemode fibre, this drastically reduced the cross-talk between cores. The fibre loss was as low as 0.18dB/km. There were also a few transmission mode division multiplexing experiments on 2 or few mode fibres. So it seems that the industry is taking steps to help cope with the so-called capacity crunch that is looming as internet data rates continue to grow exponentially.

Exhibition
It’s good to see some British companies exhibiting at the show including Polatis with their very low loss high port count optical switches, Arden Photonics with their world-leading products for encircled flux measurement and control, PE Fiberoptics with their factory and field test equipment for characterising fibres.

I think that, for me, the highlight of the show was the new in-band measurement system from JDSU that made its first public appearance. It can monitor live traffic on the network using a polarisation diverse coherent detection system and polarisation controller. This effectively provides an ultra high resolution polarisation diverse OSA, that can be used to measure in-band OSNR, in-band DGD (and PMD if enough wavelengths are measured). The resolution of the OSA is so good that characteristic features of particular modulation formats and data rates can be identified.

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