Optical multi-channel phase stabilization for programmable interferometers

[0001] A method of operating a multi-channel optical interferometer (13, 17) with at least n+1 channels is suggested such that for performing phase stabilization or phase tuning the n channels corresponding to n input channels and n output channels and the at least one spare channel is set up as common reference channel (32) that is interfering with each of the n channels.
[0002] For phase tuning and/or phase stabilization at least one phase modulator (10) is located at the input of each of the n input channels and an individual control signal for each of the n channels is generated by demodulation of a signal based on the reference channel (32) with an individual phase-locked-loop (PLL) (31) for each of the n channels and processing the demodulated signal into a control signal and feedback the control signal to the phase modulator (10) of the corresponding input channel.