Fig. 1. Schematic diagram of beam offset

Fig. 2. Schematic diagram of focal plane fusion

Fig. 3. Schematic of the SD-OCT system

Fig. 4. Full range SD-OCT image. (a) Zero delay set outside the sample; (b) Zero delay set inside the sample

Fig. 5. Removing conjugate mirror at different offset distances. （a） −0.8 mm; （b） 0.4 mm; （c） 0.8 mm

Fig. 6. Schemaic of image weighted superposition

Fig. 7. OCT scanning images of removing complex conjugate images by focusing the beam at different depths of the sample . （a） 0 mm; （b） 0.8 mm; （c） 1.6 mm; （d） Weighted superposition of beam focusing at different depth focal planes

Fig. 8. (a)-(b) Original images of colon tissue at different positions; (c)-(d) Colon tissue image after extended depth

Fig. 9. One-dimensional depth spectral data of colon tissue