Hi Yu,
Would you be able to elaborate on what you mean by wanting to create a file like structure?
For the diagram you provided I would consider using a bidirectional coupler since you require a coupler with 3 outputs. The setting for either component can be seen by double clicking the component. If you know what frequency is required you can put that value into the frequency value of the optical Gaussian pulse generator. So for example if you are modelling a lidar sensor you might choose a frequency of 193thz or 316thz. If you chose the coupler to be wavelength dependent you should adjust the wavelength of the coupler according to the frequency of the pulse selected.
Best,
Josh