Improvement in dynamic range limitation of swept source optical coherence tomography by true logarithmic amplification.

We previously demonstrated, with both theoretical and experimental studies, the dynamic range limitation with spectral domain optical coherence tomography (OCT) relative to time domain OCT. A significant portion of this limitation was due to the difference of analog/digital conversion. In this paper, a new method of true logarithmic amplification is discussed theoretically and tested experimentally to increase the dynamic range of a swept source OCT. With the current experimental setup, an increase of the dynamic range by about 6 dB was obtained.