14 March 2011

Bell Labs demos first fully integrated optical OFDM generator based on InP PICs

Alcatel-Lucent of Paris, France says that, at the Optical Fiber Communication Conference & Exposition/National Fiber Optic Engineers Conference (OFC/NFOEC 2011) in Los Angeles, its research arm Bell Labs demonstrated a range of next-generation technology advances addressing some of the most pressing challenges facing the optical industry: satisfying exponential growth in demand for network capacity and higher data rates while contending with increasingly severe technical limitations and cost constraints.

The solutions presented feature a range of techniques that enable the transmission of data at much higher bit rates and over longer distances than what is currently possible. This is accomplished by: applying higher-order signal modulation to achieve greater spectral efficiencies; heightening the sensitivity of optical receivers to a point approaching their fundamental limit; and exploiting new multimode transmission to increase the capacity of optical networks by orders of magnitude:

• Doubling spectral efficiencies — Spectral efficiency gains have been doubled to achieve a per line transmission rate of 256Gb/s over a distance of 400km, which is more than twice the rate achievable today with the 100Gb/s systems that are just coming on the market. The solution makes use of a high-powered electronic circuit that converts analog signals to digital and employs a 64-QAM (quadrature amplitude modulation) scheme.

• Achieving record modulation/receiver sensitivity — The technique halves the number of photons needed to transmit information and achieves a record degree of sensitivity by applying an advanced 16-ary-pulse-position-modulation scheme.

• Opening a new era of research in optical transmission —Alcatel-Lucent claims that this is the first demonstration of transmission over a new multimode fiber type that has the potential to increase the capacity of a single fiber strand by an order of magnitude. The demonstration takes advantage of advanced fiber design, digital signal processing, and sophisticated mode or core coupling.

Bell Labs also demonstrated what is claimed to be the first fully integrated optical orthogonal frequency division multiplexing (OFDM) generator based on photonic integrated circuits using indium phosphide (InP). It reckons that this is a key advance in making OFDM systems that are cost and power efficient enough for practical use.

Finally, Bell Labs presented specifications for new transport network protocols that will enable enterprises to more easily access large-scale data processing capabilities (high-performance computing) while facilitating outsourcing of their computing infrastructure (cloud computing). The firm demonstrated how network service providers will be able to maintain contracted levels of service for business applications delivered from the cloud using the new protocol specifications in conjunction with high-speed wavelength-switched optical network connections that can be configured on the fly.

Alcatel-Lucent reckons that these innovations represent significant advances in the evolution of optical transmission over the mid to longer term by being able to accommodate demand for increasingly higher transmission speeds required to meet rapidly increasing demand for bandwidth.

Tags: Alcatel-Lucent Bell Labs InP PICs

Visit: www.alcatel-lucent.com

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