400G, PAM-4 system test; T&M collaboration demos platform

March 11, 2016 // By Graham Prophet
A collaboration of Teledyne LeCroy, Coherent Solutions, Anritsu and Oclaro is to demonstrate a practical test systems for 400G communications, at the forthcoming OFC 2016 (Optical Fibre Communication) event (20-24 March, 2016) in Anaheim, California. The test platform combines a new DAC-based 56 Gbaud PAM4 generator with the highest-bandwidth coherent transmitter and optical modulation analyser available.

The joint effort aims to demonstrate the highest performance single-carrier 16QAM signal generation and analysis capabilities available at 56 Gbaud. The platform combines instruments for generating, transmitting, receiving and analysing coherent optical signals at 400G rates. Anritsu’s MP1800A Signal Quality Analyser and G0361A high-speed DAC generate the high-quality 56Gbaud, PAM4 RF signal (112 Gbps). Coherent Solutions’ IQTransmitter then uses Oclaro’s latest 40GHz LiNbO3 modulator to turn these PAM4 RF signals into an optical 16QAM signal.

New modulation-format-independent Automatic Bias Control (ABC) technology, also from Coherent Solutions, automatically optimises and stabilises the signal. Teledyne LeCroy’s 65 GHz LabMaster 10-65Zi-A high-bandwidth real-time oscilloscope combines with the 70 GHz IQS70 coherent optical receiver and Optical-LinQ integrated OMA software to accurately characterie the modulated optical signal.


“Being able to generate a high-quality 16QAM signal at rates as high as 56GBaud using commercially available instruments is a major milestone in the pathway to single-carrier 400G. It is also a great way to showcase the latest products in the coherent communications ecosystem,” said Andy Stevens, CEO of Coherent Solutions.


Anritsu’s MP1800A Signal Quality Analyzer (SQA) is a Bit Error Rate tester offering a suite of test capabilities to support complete signal and transmission integrity analysis. In the demonstration, the MP1800A will be integrated with the G0361A, a 64 Gbaud 2-bit D/A Converter (DAC) with dual-channel 2×1 multiplexers. The solution featuring the G0361A and MP1800A BERT eliminates the complex setup and configuration issues associated with legacy systems while also minimising capital equipment costs.


“The 400GbE Ethernet standard now under investigation uses faster symbol bit rates and more lanes, as well as the PAM modulation method to increase the transfer capacity per unit time. As will be shown in the demonstration, connecting the new G0361A to the MP1800A SQA offers support for generating high-baud-rate PAM4 signals to help move next-generation technology forward,” said Hiroshi Goto, Digital/Optics Business Development Manager, Anritsu Company.


Coherent Solutions’ IQTransmitter