A Time Domain Optical Coherence Tomography system using a modulation scheme multiplexes the scanning range of the delay line into different spectral bands. Such a modulation scheme may allow for power consumption reduction compared with a single delay line element since the same modulation pattern is being used for several channels. In an example, the optical coherence tomography system may include a plurality of stages, each stage having a group delay element. The distinct group delays may be introduced to scan a sample with distinct electrical frequency bands at distinct axial scanning depth ranges.
