I need to find some information about the 'wave packet' thoery about light. Can you please tell me how I should do this.

Answer 1

There are a couple of paragraphs in

http://en.wikipedia.org/wiki/Light

you can then follow the links to

http://en.wikipedia.org/wiki/Corpuscular_theory_of_light

and

http://en.wikipedia.org/wiki/Photoelectric_effect

Answer 2

Are sure you don't mean the "wave packet" theory of matter? A particle can be represented as a Gaussian "wave packet" that spreads with time, increasing the position uncertainty at future times. Narrowing the packet width (for position accuracy) increases the spread rate, in accordance with the Heisenberg uncertainty principle.

A wave packet of light is no big deal; it would be the standard method of representing a pulse of light with physical optics.