Circuit design considerations using N-FET for a High Brightness UV-LED?
You probably want to consider the recommendation in the datasheet: "We recommend using Thorlabs’ DC2200 or LEDD1B LED current drivers"

If you still want to use voltage mode control, I would ask: do you really need to run it at full power? 

VF is a typical number than can fluctuate with temperature and vary part to part. So if your application permits it, I would run at lower currents (maybe 700mA).

The LED output power number quoted is for light output power. Since the test current used to generate this output is stated as 1400mA you can estimate the efficiency of your LED and plan for the generated heat accordingly. 

Your NFET is close to max rated spec. I would double the current rating if possible. If you don't then I would definitely use a heat sink with some thermal paste. 

One last thing that occurs to me is to add a resistor in series with the gate of the FET. Since you will be running high currents (relative to the drive capability of the GPIO), you don't want any glitches in your LED or power supply to shove a ton of current into the GPIO. A 10K resistor should do.