Artifacts cancellation in Fourier domain optical coherence tomography using balance detection

摘要

A Fourier domain optical coherence tomography system equipped with two spectrometers in balance detection is presented. The set-up was successfully used in reducing two artifacts present in Fourier domain optical coherence tomography images: autocorrelation terms and fixed pattern noise. Conditions and adjustments of spectrometer parameters are presented to ensure an anti-phase channelled spectrum modulation along the length of the two cameras for a majority of wavelengths within the optical source spectrum. By stopping the optical signal to reach one of the spectrometers, the set-up was used to compare the conditions of operation of a single camera with that of a balanced configuration. Using as a sample a tooth, balanced detection technique is compared with techniques applied to conventional single camera set-ups, based on sequential deduction of averaged spectra collected with different on/off settings for the sample or reference beams. It is concluded that balance detection performs better than single camera techniques, is more tolerant to movement, exhibits longer-term stability and can operate dynamically in real time.