In　this　study,　we　describe　a　simple　method　to　produce　signals　which　can　reveal　the　cross-sectional　information　of　samples　in　an　optical　coherence　tomography　(OCT)　system.　Instead　of　using　the　spectrometer　and　the　Fourier　transformation　calculation　in　the　conventional　spectrum　domain　(SD)　OCT　system,　we　use　a　Mach-Zehnder　interferometer　structure　of　the　spatial　heterodyne　spectrometer.　In　a　spatial　heterodyne　spectrometer,　because　each　position　on　the　photodetector　array　could　be　mapped　to　a　specific　optical　path　difference,　the　spectral　density　distribution　could　be　retrieved　with　Fourier　transformation.　And　in　an　SD-OCT　system,　cross-section　signals　are　obtained　by　conducting　Fourier　transformation　to　the　spectrum　signals.　Therefore,　in　our　OCT　system,　the　spatial　signals　captured　by　the　photodetector　array　is　related　to　the　cross-sectional　signals　obtained　in　an　SD-OCT　system.　The　theoretical　study　and　the　numerical　simulation　demonstrate　that　by　applying　our　method　in　an　OCT　system,　the　heterodyne　spectrometer　structure　could　generate　a　symmetrical　pattern　composed　of　fringes　with　high　spatial　frequency.　Then　the　photodetector　array　captures　the　pattern　to　generate　a　spatial　signal.　The　spatial　ordinate　of　this　signal　is　linearly　related　to　the　optical　depth　in　sample,　while　the　amplitude　of　the　signal　intensity　variation　is　linearly　related　to　the　intensity　of　coherent　backscattered　light　in　the　sample.　The　imaging　depth　is　theoretically　unlimited.　Also,　because　of　the　high　spatial　frequency　of　the　signal,　we　further　adjust　the　inclination　angle　in　the　heterodyne　spectrometer　structure　to　visualize　the　signal.　©　2020　SPIE.