laser beam dimension problem.

Hi.
I've brought a laser module via Ebay (660nm 300mw) for use it in my selfmade laser show proyector.
Now my problem i beam dimension.
This module have a 5mm collimated dot beam, but i need to have a 2mm collimated beam.
You think is it possible to reduce beam dimension simply changing the collimation optic?

Second question : why red diode laser modules normally have a beam dimension greather than a blue o green module?

(sorry for my poor english :shhh

Thanks to everybody.

A pic or also a link to the auction where you buyed the module can help in giving a correct reply (we can't know what to say, if we can't know what is the module )

rudyitaly said:

why red diode laser modules normally have a beam dimension greather than a blue o green module?

Click to expand...

well red's are alway's wider :tinfoil:

Thank you wery much.
Tomorrow for me will be an holiday, i will post some photos of my module.