Next-generation coherent adds sub-carriers to capabilities

Briefing: DWDM developments

Part 2: Infinera's coherent toolkit 

Source: Infinera

Infinera has detailed coherent technology enhancements implemented using its latest-generation optical transmission technology. The system vendor is still to launch its newest  photonic integrated circuit (PIC) and FlexCoherent DSP-ASIC but has detailed features the CMOS and indium phosphide ICs support.

The techniques highlight the increasing sophistication of coherent technology and an ever tighter coupling between electronics and photonics.    

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Finisar adds silicon photonics to its technology toolkit

• Finisar revealed its in-house silicon photonics design capability at ECOC
• The company also showed its latest ROADM technologies: a dual wavelength-selective switch and a high-resolution optical channel monitor.
• Also shown was an optical amplifier that spans 400km fibre links 

These two complementary technologies [VCSELs and silicon photonics] work well together as we think about the next-generation Ethernet applications.

Rafik Ward

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Xtera demonstrates 40 Terabit using Raman amplification

Feature: 100 Gig and Beyond. Part 2

• Xtera's Raman amplification boosts capacity and reach
• 40 Terabit optical transmission over 1,500km in Verizon trial
• 64 Terabit over 1,500km in 2015 using a Raman module operating over 100nm of spectrum  

Herve Fevrier

Optical transport equipment makers continue to research techniques to increase the data carried long distances over a fibre without sacrificing reach. The techniques include signal processing of the transmit signal to cram data-carrying channels closer in the C-band, advanced soft-decision forward error correction (SD-FEC) and receiver signal processing to counter transmission impairments.

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Verizon on 100G+ optical transmission developments

Source: Gazettabyte

Feature: 100 Gig and Beyond. Part 1:

Verizon's Glenn Wellbrock discusses 100 Gig deployments and higher speed optical channel developments for long haul and metro. 

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Merits and challenges of optical transmission at 64 Gbaud

u2t Photonics announced recently a balanced detector that supports 64Gbaud. This promises coherent transmission systems with double the data rate. But even if the remaining components - the modulator and DSP-ASIC capable of operating at 64Gbaud - were available, would such an approach make sense?

Gazettabyte asked system vendors Transmode and Ciena for their views.

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u2t Photonics pushes balanced detectors to 70GHz

• u²t's 70GHz balanced detector supports 64Gbaud for test and measurement and R&D
• The company's gallium arsenide modulator and next-generation receiver will enable 100 Gigabit long-haul in a CFP2

"The performance [of gallium arsenide] is very similar to the lithium niobate modulator"

Jens Fiedler,  u²t Photonics

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Infinera speeds up network restoration

• Claimed to be the only hardware implementation of the Shared Mesh Protection protocol
• Provides network-wide protection against multiple network failures
• The chip is already within the DTN-X system; protocol will be activated this year

Pravin Mahajan, Infinera

Infinera has developed a chip to speed up network restoration following faults.

The chip implements the Shared Mesh Protection (SMP) protocol being developed by the International Telecommunication Union (ITU) and the Internet Engineering Task Force (IETF) and Infinera believes it is the only vendor with hardware acceleration of the protocol.

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