Process and device for characterising an optical source

A device for characterizing an optical source, said device comprising:

• a calculation unit, arranged and/or programmed in order to control in what state a source is found and/or receive items of information on the state of a source or the different explored states of a source, the calculation unit being arranged and/or programmed in order to know a constant (b);
• at least one sensor, arranged in order to receive at least a part of the first radiation generated by the source according to different explored states of the source, each sensor comprising a Fabry-Perot etalon followed by a photodiode, each sensor being arranged in order to measure a signal for each explored state of the source as a function of the at least one part of the first radiation received by this sensor at this explored state of the source;
• the calculation unit, being arranged and/or programmed in order to calculate, from the signals measured by each sensor and for each explored state of the source, a first data item representative of the wavelength of the first radiation, the calculation unit being arranged and/or programmed in order to carry out a selection, for each explored state of the source, of a selected value of the first data item from among several possible values, said selection comprising eliminating values of the first data item that do not correspond to the constant (b) modulo the free spectral range expressed in the units of the first data item.