| 摘要 |
Optical apparatus for selecting a predetermined item of information from a coherent optical signal carrying a set of digital data, the said optical apparatus comprising: - an input for the said coherent optical signal; - an optical-optical device connected to the said input for propagating the said coherent optical signal, the said optical-optical device being capable of generating a highly incoherent light having a predetermined coherence time and of transferring the said set of digital data carried by the said coherent optical signal to the said highly incoherent light in such a way as to provide at its output a highly incoherent optical signal carrying the said set of digital data, - an optical beam splitter for cloning the said highly incoherent optical signal into at least two highly incoherent optical signals, the said optical beam splitter having an input connected to the said optical-optical device and at least two outputs for the said at least two highly incoherent optical signals; - at least two optical delay lines connected to the said at least two outputs of the said optical beam splitter, the said at least two optical delay lines having different wavelengths from each other, the difference in length between the said at least two optical delay lines being such that the said at least two highly incoherent optical signals are delayed with respect to each other by a predetermined time, the said predetermined time being greater than the said predetermined coherence time of the said highly incoherent optical signal and being chosen in accordance with the said predetermined item of information which is to be selected; - an optical coupler with at least two inputs connected to the said at least two optical delay lines, and one output, the said coupler being capable of recombining the said at least two highly incoherent optical signals into a single highly incoherent optical output signal having an intensity which is at a maximum in the presence of the said predetermined item of information which is to be selected. |
