The Keysight N7711A and N7714A tunable lasers are single-port and four-port sources, available with C-band or L-band wavelength coverage. All models can reach any wavelength point within their specified wavelength in the C- and L-band range. The narrow linewidth and offset grid fine-tuning capability make them ideal sources for the realistic loading of the latest transmission systems. In system loading applications, it may be preferable to grid-tune the lasers like system transmitters, simply by changing the channel index. The channel grid is adjustable to standard ITU-T grid spacing like 50 GHz, and to arbitrary grids. The Keysight N7711A and N7714A tunable lasers are available in a compact format with half-rack width and one rack-unit height. This format makes them the right choice for high channel-count system load applications.