Wits Ruby Laser
The ruby laser is a solid-state laser that uses a synthetic ruby crystal as its gain medium. It produce pulses of visible light at a wavelength of 694.3 nm, which is a deep red color, typical ruby laser pulse lengths are on the order of a millisecond.
![Wits Ruby Laser](http://eqdb.nrf.ac.za/sites/default/files/styles/equipment_image/public/equipment/images/220px-5_maiman_laser_components.jpg?itok=0XtmG6KS)