Method for phase tuning and phase stabilization of multiple interferometers , preferably interferometers used for the measurement of energy-time entanglement, whereby the method comprises: i) generation of an electronic modulation signal; ii) phase modulation of a laser beam by a phase modulator and the electronic modulation signal; iii) passing the modulated laser beam through the interferometers, whereby the interferometers are Mach-Zehnder interferometers and/or Michelson interferometers; iv) detection of the modulated laser beam by at least one detector ; v) demodulation of the detected signal or signals in order to generate an error signal for each interferometer; vi) tuning and/or stabilization of the interferometers by a feedback of the respective error signal to a respective movable element of each interferometer, characterized in that the electronic modulation signal in step i) comprises a carrier frequency ω c and a modulation frequency ω m , and the modulation in step ii) generates frequency dependent sidebands, preferably ω c -sidebands corresponding to the carrier frequency ω c and ω m - sidebands corresponding to the modulation frequency ω m , and the demodulation of the detected signal or signals in step v) is realized by mixing the detected signal or signals with a signal in phase and with the frequency of the modulation frequency ω m , and the modulation signal comprises for each interferometer i a carrier frequency ω ci and/or a modulation frequency ω mi , and that an individual modulation frequency ω mi is used for each interferometer i, and/or that an individual carrier frequency ω ci for each interferometer i is modulated by an individual modulation frequency ω mi . i) generation of an electronic modulation signal; ii) phase modulation of a laser beam by a phase modulator and the electronic modulation signal; iii) passing the modulated laser beam through the interferometers, whereby the interferometers are Mach-Zehnder interferometers and/or Michelson interferometers; iv) detection of the modulated laser beam by at least one detector ; v) demodulation of the detected signal or signals in order to generate an error signal for each interferometer; vi) tuning and/or stabilization of the interferometers by a feedback of the respective error signal to a respective movable element of each interferometer, the electronic modulation signal in step i) comprises a carrier frequency ω c and a modulation frequency ω m , and the modulation in step ii) generates frequency dependent sidebands, preferably ω c -sidebands corresponding to the carrier frequency ω c and ω m - sidebands corresponding to the modulation frequency ω m , and the demodulation of the detected signal or signals in step v) is realized by mixing the detected signal or signals with a signal in phase and with the frequency of the modulation frequency ω m , and the modulation signal comprises for each interferometer i a carrier frequency ω ci and/or a modulation frequency ω mi , and that an individual modulation frequency ω mi is used for each interferometer i, and/or that an individual carrier frequency ω ci for each interferometer i is modulated by an individual modulation frequency ω mi . <EOS>