Increasing the imaging depth of spectral-domain OCT by using interpixel shift technique.

A simple pixel shift technique is proposed to double the spectral sampling rate and enhance the signal to noise ratio of spectral-domain optical coherence tomography (SDOCT) in the 1.3 um wavelength range. Both theoretical analysis and experimental comparison are presented. The results show that interpixel shifted SDOCT can not only double the depth of field of SDOCT image but also eliminate the artifacts induced by aliasing effect, thus improving image contrast in areas with large depths (e.g., Delta z > or = 1.5 mm). If combined with endoscopic OCT, this technique has the potential to enhance in vivo diagnosis of biological tissues that require a larger field of view in the axial direction, such as cartilage degeneration and bladder tumors with deep asperities or invaginations.