A system for creating an adjustable delay in an optical signal. The system has an input interface for receiving an optical input signal. The system has a first optical modulator configured to shift the frequency of the optical input signal depending on a setting of the first optical modulator, thereby generating a modulated optical signal. The system includes at least two frequency selective reflectors configured to reflect the modulated optical signal, thereby providing a reflected signal. The system has a control circuit that adapts the setting of the first optical modulator such that a frequency shift of the optical input signal introduced by the first optical modulator is set by the control circuit. The frequency shift introduced by the first optical modulator corresponds to an operational frequency of one of the at least two frequency selective reflectors associated with the setting of the first optical modulator. The system has an output fiber that receives the reflected signal from the corresponding frequency selective reflector.