When parallel light rays fall upon a diffraction grating, a Fraunhofer diffraction pattern can be observed.

Things that needs to be changed:
1.) instead of "diffraction lattice", we speak of a "diffraction grating".
2.) I would prefer to add "rays" to "incoming parallel light".
3.) Instead of "Fraunhofer interference", it is much commoner to speak of "Fraunhofer diffraction". Interference and diffraction are intimately related, however, in this context, diffraction is used.
4.) Instead of "thus resulting in" you have several better options. "give rise to" is one, adding "pattern + observed" is another.

You can compose several good English sentences by including these elements. My suggestion is certainly not the only possibility.