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Wednesday
Oct162013

ECOC 2013 review - Part 2

The final part of some of the notable product announcements made at the recent European Conference on Optical Communication (ECOC) exhibition held in London.  

  • Oclaro's Raman and hybrid amplifier platform for new networks
  • MxN wavelength-selective switch from JDSU
  • 200 Gigabit multi-vendor coherent demonstration
  • Tunable SFP+ designs proliferate
  • Finisar extends 40 Gigabit QSFP+ to 40km
  • Oclaro’s tackles wireless backhaul with 2km SFP+ module

 

Finisar's 40km 40 Gig QSFP+ demo. Source: Finisar

Amplifier market heats up

Oclaro detailed its high performance Raman and hybrid Raman/ Erbium-doped fibre amplifier platform. "The need for this platform is the high-capacity, high channel rates being installed [by operators] and the desire to be scalable - to support 400 Gig and Terabit super-channels in future," says Per Hansen, vice president of product marketing, optical networks solutions at Oclaro.

"Amplifiers are 'hot' again," says Daryl Inniss, vice president and practice leader components at market research firm, Ovum. For the last decade, amplifier vendors have been tasked with reducing the cost of their amplifier designs. "Now there is a need for new solutions that are more expensive," says Inniss. "It is no longer just cost-cutting."

Amplifiers are used in the network backbone to boost the optical signal-to-noise ratio (OSNR). Raman amplification provides significant noise improvement but it is not power efficient so a Raman amplifier is nearly always matched with an Erbium one. "You can think of the Raman as often working as a pre-amp, and the Erbium-doped fibre as the booster stage of the hybrid amplifier," says Hansen. System houses have different amplifier approaches and how they connect them in the field, while others build them on one card, but Raman/ Erbium-doped fibre are almost always used in tandem, says Hansen.

Oclaro provides Raman units and hybrid units that combine Raman with Erbium-doped fibre. "We can deliver both as a super-module that vendors integrate on their line cards or we can build the whole line card for them" says Hansen.

 

The Raman amplifier market is way bigger than people have forecast 

 

Since Raman launches a lot of pump power into the fibre, it is vital to have low-loss connections that avoid attenuating the gain. "Raman is a little more sensitive to the quality of the connections and the fibre," says Hansen. Oclaro offers scan diagnostic features that characterise the fibre and determine whether it is safe to turn up the amplification.

"It can analyse the fibre and depending on how much customers want us to do, we can take this to the point that it [the design] can tell you what fibre it is and optimise the pump situation for the fibre," says Hansen. In other cases, the system vendors adopt their own amplifier control.

Oclaro says it is in discussion with customers about implementations. "We are shipping the first products based on this platform," says Hansen.

"[The] Raman [amplifier market] is way bigger than people have forecast," says Inniss. This is due to operators building long distance networks that are scalable to higher data rates. "Coherent transmission is the focal point here, as coherent provides the mechanism to go long distance at high data rates," says Ovum analyst, Inniss. 

 

Wavelength-selective switches

JDSU discussed its wavelength-selective switch (WSS) products at ECOC. The company has previously detailed its twin 1x20 port WSS, which has moved from development to volume production.

At ECOC, JDSU detailed its work on a twin MxN WSS design. "It is a WSS that instead of being a 1xN - 1x20 or a 1x9 - it is an MxN," says Brandon Collings, chief technology officer, communications and commercial optical products at JDSU. "So it has multiple input and output ports on both sides." Such a design is used for the add and drop multiplexer for colourless and directionless reconfigurable optical add/ drop multiplexers (ROADMs).

"People have been able to build colourless and directionless architectures using conventional 1xN WSSes," says Collings. The MxN serves the same functionality but in a single integrated unit, halving the volume and cost for colourless and directionless compared to the current approach.

JDSU says it is also completing the development of a twin multicast switch, the add and drop multiplexer suited to colourless, directionless and contentionless ROADM designs.

 

200 Gigabit coherent demonstration

ClariPhy Communications, working with NeoPhotonics, Fujitsu Optical Components, u2t Photonics and Inphi, showcased a reference-design demonstration of 200 Gig coherent optical transmission using 16 quadrature amplitude modulation (16-QAM).

For the demonstration, ClariPhy provided the coherent silicon: the digital-to-analogue converter for transmission and the receiver analogue-to digital and digital signal processing (DSP) used to counter channel transmission impairments. NeoPhotonics provided the lasers, for transmission and at the receiver, u2t Photonics supplied the integrated coherent receiver, Fujistu Optical Components the lithium niobate nested modulator while Inphi provided the quad-modulator driver IC.  

ClariPhy is developing a 28nm CMOS Lightspeed chip suited for metro and long-haul coherent transmission. The chip will support 100 and 200 Gigabit-per-second (Gbps) data rates and have an adjustable power consumption tailored to the application. The chip will also be suited for use within a coherent CFP module.    

"All the components that we are talking about for 100 Gig are either ready or will soon be ready for 200 and 400 Gig," says Ferris Lipscomb, vice president of marketing at NeoPhotonics. To achieve 400Gbps, two 16-QAM channels can be used.

 

The DWDM market for 10 Gig is now starting to plateau

 

Tunable SFPs

JDSU first released a 10Gbps SFP+ optical module tunable across the C-band in 2012, a design that dissipates up to 2W. The SFP+ MSA agreement, however, calls for no greater than a 1.5W power consumption. "Our customers had to deal with that higher power dissipation which, in a lot of cases, was doable," says JDSU Collings.

 

Robert Blum, Oclaro

JDSU's latest tunable SFP+ design now meets the 1.5W power specification. "This gets into the MSA standard's power dissipation envelop and can now go into every SFP+ socket that is deployed," says Collings. To achieve the power target involved a redesign of the tunable laser. The tunable SFP+ is now sampling and will be generally available one or two quarters hence.

Oclaro and Finisar also unveiled tunable SFP+ modules at ECOC 2013. "The design is using the integrated tunable laser and Mach-Zehnder modulator, all on the same chip," says Robert Blum, director of product marketing for Oclaro's photonic components. 

Neither Oclaro nor Finisar detailed their SFP+'s power consumption. "The 1.5W is the standard people are trying to achieve and we are quite close to that," says Blum.

Both Oclaro's and Finisar's tunable SFP+ designs are sampling now.

Reducing a 10Gbps tunable transceiver to a SFP+ in effect is the end destination on the module roadmap. "The DWDM market for 10 Gig is now starting to plateau," says Rafik Ward, vice president of marketing at Finisar. "From an industry perspective, you will see more and more effort on higher data rates in future."   

 

40G QSFP+ with a 40km reach

Finisar demonstrated a 40Gbps QSFP+ with a reach of 40km. "The QSFP has embedded itself as the form-factor of choice at 40 Gig," says Ward.

Until now there has been the 850nm 40GBASE-SR4 with a 100m reach and the 1310nm 40GBASE-LR4 at 10km. To achieve a 40km QSFP+, Finisar is using four uncooled distributed feedback (DFB) lasers and an avalanche photo-detector (APD) operating using coarse WDM (CWDM) wavelengths spaced around 1310nm. The QSFP+ is being used on client side cards for enterprise and telecom equipment, says Finisar.

 

Module for wireless backhaul

Oclaro announced an SFP+ that supports the wireless Common Public Radio Interface (CPRI) and Open Base Station Architecture Initiative (OBSAI) standards used to link equipment in a wireless cell's tower and the base station controller.

Until now, optical modules for CPRI have been the 10km 10GBASE-LR4 modules. "You have a relatively expensive device for the last mile which is the most cost sensitive [part of the network]," says Oclaro's Hansen.

Oclaro's 1W SFP+ reduces module cost by using a simpler Fabry-Perot laser but at the expense of a 2km reach only. However, this is sufficient for a majority of requirements, says Hansen. The SFP supports 2.5G, 3Gbps, 6Gbps and 10Gbps rates. "CPRI has been used mostly at 3 Gig and 6 Gig but there is interest in 10 Gig due to growing mobile data traffic and the adoption of LTE," says Hansen.

The SFP+ module is sampling and will be in volume production by year end.

 

For Part 1, click here

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