Spectral-domain optical coherence tomography: Removal of autocorrelation using an optical switch

A novel spectral-domain optical coherence tomography (SD-OCT), in which the self-interferogram of the object wave and the standard SD-OCT interferogram are acquired asynchronously using an optical switch in the reference arm, is presented. After Fourier transformation, the autocorrelation of the object is removed simply by subtraction from the standard SD-OCT image. The measured sensitivity is 103.5dB at z=0.115mm, and it gradually reduces to 84.1dB at z=3.275mm. The axial resolution is 15μm in the air. In vivo images of human skin are presented to demonstrate the performance of autocorrelation removal.