VERFAHREN UND OPTISCHES SYSTEM ZUR AUFZEICHNUNG/WIEDERGABE VON INFORMATION AUF EINEM AUFZEICHNUNGSMEDIUM

摘要

PCT No. PCT/FR94/01517 Sec. 371 Date Aug. 23, 1995 Sec. 102(e) Date Aug. 23, 1995 PCT Filed Dec. 22, 1994 PCT Pub. No. WO95/17747 PCT Pub. Date Jun. 29, 1995Method, system and recording medium in which the writing of information is achieved by the use of a write beam including the superposition of a first optical beam at a first wavelength and of a second beam at a second wavelength less than the first wavelength. Reading is done by the use of a second optical beam at the second wavelength. The material of the recording medium is a non-linear material exhibiting a recording threshold situated between the maximum of the sum of the energies of the two beams and an energy level situated in the vicinity of the maximum energy of the first beam.