OPTO-ELECTRONIC FREQUENCY DIVIDER CIRCUIT AND METHOD OF OPERATING SAME

摘要

The circuit includes an electro-optical mixer, such as an electro-optical Mach-Zehnder modulator, with non-linear behaviour. The modulator receives as input an optical signal at the frequency to be divided, in addition to an electric signal at a given frequency, usually corresponding to the frequency deriving from such division. The output optical signal from modulator exhibits a modulation spectrum containing the frequency difference between the frequency to be divided and at least one harmonic of the frequency of the above electric signal. After having been converted into an electric signal, the output signal of the mixer is subjected to a filtering action to extract the above frequency difference component. This latter one is then used both as electrical signal for the mixing, and as output signal from the divider. The preferred application is to OTDM systems, to extract a synchronism signal at tributary signal frequency.