Speckle reduction in optical coherence tomography using angular compounding by B-scan Doppler-shift encoding

We propose a novel method for speckle reduction for optical coherence tomography based on angular compounding by B-scan Doppler-shift encoding (AngularCBD). By decentering the probe beam from the pivot of a scanning mirror, the illumination angle represented by different components of the beam can be encoded in Doppler shift. Compounding multiple images reconstructed from different Doppler-shift bands, we can suppress speckle without sacrificing image acquisition speed. Speckle reduction with AngularCBD is demonstrated by imaging a phantom and tissue sample in vitro and in vivo.