N7718C Optical Reference Transmitter

Optical transceiver manufacturers and optical interconnect solution providers need to validate standards compliance and ensure interoperability at data rates beyond 200 Gbps per lane. Meanwhile, research for data rates at 400 Gbps per lane has already started.
 

The Keysight N7718C Optical Reference Transmitter is suitable for any intensity-modulated signal format with rates of 120 Gbaud and beyond. It operates in the optical O-band (1.3 µm window). Users can connect the optical input to either the built-in 1310 nm DFB laser or a tunable laser to cover LR4, ER4, CWDM4, or other wavelength grids.
 

The turnkey Keysight N4917DJCA optical receiver stress test solution consists of the M8050A BERT, M8053A interference source and the N7718C. Rather than using in-house transmitters with a given signal quality, optical receiver designers can use the solution to simulate a 120 Gbaud optical transmitter to validate their receivers under variable conditions. Those conditions include optical extinction ratio and TDECQ, as well as stress conditions like noise, jitter, and interference.
 

The N7718C optical reference transmitter, driven by the M8050 Series BERT, generates clean and stressed signals. This approach enables the automated testing of optical receiver designs for compliance with the upcoming IEEE 802.3dj standard.
 

Paired with the M8199B, the industry’s fastest AWG, the N7718C can generate IM-DD signals, such as NRZ, PAM4, PAM6, and PAM8 waveforms. This capability enables research for transmission at 448 Gbps net bitrate per lane, paving the way for 3.2 Tbps links.
 

Because the N7718C has low Vpi, users do not always need an RF amplifier, which would add jitter and noise, to achieve a cleaner optical signal.
 

The N7718C’s convenient automated bias-control mode works without dithering in the quadrature point. Therefore, it will not inject any unwanted spectral components to the optical signal.