Oclaro Inc of San Jose, CA, USA (which provides components, modules and subsystems for optical communications) has announced early sampling of a 400Gb/s high electro-optic bandwidth lithium niobate (LiNbO3) external modulator for designing and testing 400G and higher networks on a single wavelength. Designed to enable 400G and beyond speeds on a single wavelength or carrier, Oclaro's 400G lithium niobate external modulator is a high electro-optic bandwidth polarization multiplexed quad parallel Mach-Zehnder (PM-QMZ) device that integrates into a hermetic package an input beam splitter, four parallel Mach-Zehnder modulators configured for I-Q modulation, a polarization combiner, and monitor photodiodes for power and bias control.
Key features include the following:
3dB electro-optic bandwidth exceeding 35GHz; smooth optical response up to 50GHz, enabling a symbol rate of up to 64Gbaud; an extinction ratio above 25dB to enable complex modulation formats; and insertion loss below 13dB for high efficiency.
By eliminating the need to use two wavelengths with the 16-QAM modulation format, the new 400G external modulator is designed to enable networking companies to more quickly design and test next-generation, high-speed networks that deliver the highest level of performance and reliability.
"To scale to 400G speeds and higher in the future, optical networking companies are improving spectral efficiency and lowering the cost per bit in fiber transmission systems, something that is not economical with two wavelengths," says chief commercial officer Adam Carter.
As optical network capacities continue to increase to meet the rising demands for bandwidth, optical designers have turned to coherent modulation techniques to obtain the highest transmission speeds and lowest bit error rates (BERs) in their networks, Oclaro says. The most advanced systems have port capacities of up to 400G. While in the past they were limited to using two wavelengths to achieve this, they can now achieve 400G capacity on a single wavelength, making it easier to deliver the increased bandwidth telecom operators are demanding, the firm adds.
