System and method for determining a modal property of a quantum state using two-time correlation measurements

A system for determining a modal property of a quantum state using two-time correlation measurements, the system comprising:

• a quantum light source generating a given optical pulse having a given frequency, a given pulse time duration and a quantum state, the quantum state having the modal property;
• a local pulse train generator having:
• a laser source generating a local optical signal having a local frequency associated to the given frequency;
• an optical modulator optically coupled to the laser source and modulating the local optical signal;
• and a programmable wave generator electrically coupled to the optical modulator and supplying electrical waveforms to the optical modulator for said modulating, the electrical waveforms supplied to the optical modulator corresponding to one or more mode bases, said modulating including:
• forming a train of local optical pulses from the local optical signal, the train of local optical pulses being distributed within the given pulse time duration;
• and
• shaping each local optical pulse in the train of local optical pulses into a temporal shape corresponding to the one or more mode basis via the electrical waveforms suppled to the optical modulator by the programmable wave generator;
• and
• a homodyne detector optically coupled to the quantum light source and to the local pulse train generator, the homodyne detector performing two-time correlation measurements between the given optical pulse and the train of local optical pulses, the two-time correlation measurements being indicative of the modal property of the quantum state of the given optical pulse.