>"Laser optical pickup units that are used in CD / DVD and BlueRay players to read the disc are amazing pieces of engineering with built in lasers, optical stages, filters and mirrors. These small units, that can be found in almost any electronics dumpster, <i>are a perfect starting point for building amazing scientific instruments</i>."<p>[...]<p>"...we started working on building a <i>DIY Laser Tweezer (optical trap)</i> built only from a DVD pickup and a webcam."