Please refer the script file in the example. You need to use script to load the signal.
In many many cases it is absolutely no need to use monochromatic light source. Please think it again, and read above replies.
The only cases are the listed examples for few nonlinear simulation, or you only need to know time domain result, without separating the amplitude and phase, as the simulation is at steady state which records instanteneous fields from a time monitor. You cannot use frequency domain monitors, as it violates the Fourier tranform theorem.