[Laser] LED vs Laser diode

[Alberto di Bene]

I know almost nothing about light communication, but this summer I will perform some experiments.
I have just a question which will show how ignorant I am in this field.
I bought at an ham fair a Luxeon 3W white LED. What I would like to know is how does it compare, in terms of quantity of 
light received at distance, with a laser diode ? Suppose that both are reasonably focused with a lens.
So, what is the mW equivalent from a laser diode of that 3W Luxeon LED ?

Thanks for any insights.

73  Alberto  I2PHD