Optical storage tape. Researcher observing a semiconductor laser (blue) writing data onto different layers of a roll of plastic adhesive tape. The laser is reflected by a rotating mirror (centre left) and focused onto specific points on the tape, altering the refractive index (RI) of the tape. By altering the RI at various points of the tape, information such as images, sound and computer data can be stored without the tape being unwound. This roll of tape can store up to 10 gigabytes of data. The device is being developed in Heidelberg, Germany, by the European Media laboratory (EML) in cooperation with the Mannheim University.