Hi Guys,
Re lens for laser pointers et al.
All CD/DVD drives use a single lens about 5 mm in diameter to focus the laser inside, so that the disc can be read. In all the drives that I have played with the lens is easily removed and can be re-purposed for use with a laser pointer in order to focus the beam.
A Google search "focus laser pointer" came up with lots of hits for doing this, along with lots of warnings. I also discovered that in the UK at least there is a legal limit on laser power and class. It seems that 5 mw is the maximum for non industrial lasers.
Note that using a lens does not increase the power of a laser, it only concentrates the beam into a smaller area. This in turn increases the danger of eye damage, not only due to direct illumination, but also specular reflection, which will be more from shiny surfaces. I believe that some kinds of safety glasses used in engineering reduce the risk of eye damage from this cause. I haven't done any research into eye protection of this kind.
HTH.