The read/write, magneto-optic disc drive features a system of lenses and prisms. These optics direct and focus a laser beam to the recording surface and then back to a ~photoreceptor~. The laser source sends out a beam of coherent light, which is passed through the back of a beam splitter prism. The beam is then passed through a collimating lens to keep it parallel. A focusing lens then sharpens the beam at the recording surface, heating it. The beam is then reflected back to the splitter prism, which reflects it to a photoreceptor. This receptor transmits an electronic signal to the drive processor for analysis.