Laser Tweezer

First of all,

I gonna use a <30mW Laser, to not burn your eyes use Laser-safety-goggles and become sure no one get harmed by your actions. While working on the tweezer it's safer not to wear an metallic or reflective stuff and use anodized tools.

A few more details on this development, I have built up that construction in recent weeks at the University of Tübingen for the beginner training in physics. This structure will cost quite a lot of money but who can afford it will surely have a lot of fun with it.
In this structure, polystyrene beads are used as colloids. Since the diameter is much larger than the wavelength of the laser I will add only the geometric explanation of optical tweezers.

The distances between the individual optical elements are only of secondary importance. But I will explain every part of what is important in the beam path as the laser beam and look lost.

I know this instruction is not very good but with your help and some time it will be helpfull.