First-Ever Simultaneous Wavelength Conversion Technology with No Wavelength Restriction in Next-Generation Optical Networks

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Fujitsu Laboratories Ltd. and a Fraunhofer Heinrich Hertz Institute HHI currently announced a growth of a new routine to concurrently modify a wavelengths of wavelength-division-multiplexed signals compulsory for visual communication send nodes in destiny wavelength-division-multiplexed visual networks, and have successfully tested a routine regulating high-bandwidth vigilance delivery in a operation of 1 Tbps.

In a compulsory visual wavelength acclimatisation routine any particular visual wavelength is converted into an electrical vigilance and re-transmitted during a new wavelength, that is unreal for terabit-class estimate as any wavelength requires a possess O/E/O circuit. Using a new technology, a visual wavelength acclimatisation and a polarization state are tranquil during a same time, so coexisting wavelength acclimatisation of wide-band visual signals can be achieved but restrictions on a wavelengths of a visual submit vigilance or a modulation formats. As a result, estimate can be achieved with a singular wavelength converter, regardless of a series of wavelengths multiplexed. Therefore, deliberation visual signals in additional of 1 Tbps multiplexed from 10 wavelengths, for example, a new routine can routine them regulating only one-tenth of a energy or reduction compared to before technologies that compulsory a apart circuit to modify any wavelength into an electrical vigilance and back.

By requesting this record to a visual nodes within a visual network, a use potency of a communications rope is improved, and this is approaching to minister to a some-more fast communications environment.

Details of this record will be announced during ECOC 2016 (42nd European Conference on Optical Communication), an general discussion that will be hold from Sunday, Sep 18 to Thursday, Sep 22 in Dusseldorf, Germany.

Figure 1. Wavelength row during visual send nodes

Figure 1. Wavelength row during visual send nodes


Today, visual fiber networks that support large-scale datacenters and worldly cloud-based ICT services rest on wavelength-division-multiplexing (WDM) technology, that combines visual signals of opposite wavelengths for delivery in a singular visual fiber to bond churned terminals in an visual network with high bandwidth and low latency. In new years, a bandwidth achieved per wavelength typically is 100 Gbps with a polarization-multiplexed quadrature proviso change keying modulation method(1). Progress is now being done on building record that, by augmenting a modulation multiplicity, will make it probable to grasp terabit-class high-bandwidth communications environments in a future.

Technological Issues

When joining churned terminals in an visual network, it is compulsory to equivocate collisions/contention (figure 1) by carrying a ability to modify between wavelengths since visual signals of a same wavelength can't be transmitted in a same visual fiber between a visual send nodes.

Figure 2. Examples of wavelength acclimatisation technologies

Figure 2. Examples of wavelength acclimatisation technologies

Previously, dual methods were proposed: A routine for duration acclimatisation into an electrical vigilance (left side of figure 2), and a routine regulating nonlinear visual effects and a wavelength filter (right side of figure 2). With a initial method, however, there was an emanate due to a boost in estimate latency from a mutual acclimatisation of electrical and visual signals. Another emanate was that since one acclimatisation circuit is compulsory for any wavelength, an boost in a series of multiplexed wavelengths increases a volume of consumed electricity. Likewise, with a latter method, nonetheless it enables wavelengths to be converted in one batch, a unsentimental doing is cryptic since it requires a filter component to mislay only a wavelengths of a vigilance before to conversion, origination it formidable to hoop signals with a accumulation of wavelengths.

The Newly Developed Technology

Now Fujitsu Laboratories and Fraunhofer HHI have detected a new coexisting wavelength acclimatisation routine that controls a visual wavelength acclimatisation and a polarization state during once, and have combined a antecedent wavelength acclimatisation circuit formed on this principle. Using this antecedent circuit, they succeeded in an examination to concurrently modify visual polarization multiplication multiplexed visual signals surpassing 1 Tbps. This represents a world’s initial successful doing of a coexisting wavelength acclimatisation capability that functions but any restrictions on a wavelength of a visual signals submit or a modulation format.

The newly grown record has a following features.

Figure 3. The due wavelength acclimatisation technology

Figure 3. The due wavelength acclimatisation technology

1. A world’s first: New coexisting wavelength acclimatisation record regulating a polarization filter

It is famous that by mixing an visual vigilance comprised of churned wavelengths with siphon light when inputting into a nonlinear visual medium, it is probable to beget a wavelength converted light that is still churned with a submit visual signal. Fujitsu Laboratories and Fraunhofer HHI grown a new coexisting wavelength acclimatisation record that, in suitability with a wavelength conversion, alters a polarization state of a visual signal, and, regulating a polarization filter instead of a wavelength filter used in before technologies, removes a visual vigilance before to a wavelength conversion. It afterwards extracts only a visual vigilance after a wavelength conversion. By determining a spacing of a siphon light’s wavelength, a wavelength after acclimatisation can be tranquil during a user’s discretion.

2. Simultaneous wavelength acclimatisation record for polarization-multiplexed visual signals

The dual components of a visual vigilance include of a plumb polarized call and a horizontally polarized wave. By separating them, behaving a wavelength acclimatisation in parallel, and afterwards recombining a signal, Fujitsu Laboratories and Fraunhofer HHI grown a record for polarization-multiplexed signals. Using a antecedent circuit formed on this principle, they achieved coexisting acclimatisation of polarization-multiplexed signals surpassing 1 Tbps.


Whereas, previously, for a wavelength acclimatisation of high-bandwidth visual vigilance of 1 Tbps, for example, 10 converters were compulsory for acclimatisation into electrical signals, coexisting acclimatisation regulating only one converter is probable regulating a new technology. This enables to grasp a homogeneous duty while immoderate one-tenth a energy or reduction than formerly required. In addition, since there are no restrictions on a wavelengths before or after conversion, this record will minister to a origination of next-generation visual networks in that a pattern of a network can be flexibly modified.

Future Plans

Targeting unsentimental doing around 2020, Fujitsu Laboratories and Fraunhofer HHI will work on serve improvements in acclimatisation potency as good as improvements in a feasibility of volume prolongation that are indispensable for commercialization of this technology.

(1) Polarization-multiplexed quadrature proviso change keying modulation method

An visual modulation routine that has turn a de facto attention customary for 100 Gbps visual delivery systems. It combines quadrature proviso modulation with polarization-multiplexing technology, in that a plumb polarized call and a horizontally polarized call of a visual vigilance are multiplexed to double a delivery capacity.

Source: ACN