Optical recording and/or reproducing apparatus and method utilizing stimulated photon echo

摘要

The recording method and apparatus according to this invention is an "optical recording method utilizing a simulated photon echo" in which information is recorded by irradiating data and record excitation lights at the same time or at different times on the same location of a recording medium, and in which the delay time of a record excitation light electric field and a data light electric field is recorded as the information by use of a common incoherent light split into two equal parts: the data light and the record excitation light. In the reproducing method and apparatus according to this invention, reproducing excitation and probe lights are illuminated on the recording medium and the stimulated photon echo light emitted from the medium by illumination of the reproducing excitation light overlaps the probe light. The "stimulated photon echo" reproducing the information is utilized by converting the synthetic light obtained from the overlap into an electrical signal at a photo detector. A common incoherent light is split into two equal parts, the reproducing excitation and the probe lights, whereby the delay time of the reproducing excitation light electric field and the probe light electric field is set to predetermined values, or a first predetermined value is swept to a second predetermined value.