Tomography technology based on spatial light modulator

On the basis of traditional interferometric holography technology, we propose a purely optical three-dimensional display holography technology. A spatial light modulator is used to realize wavefront reproduction of object beams from a real object and holographic images of the object are presented on different planes through tomography. First, a wavefront sensor is used to acquire the wavefront information of the real object. After that, a single fast Fourier transform algorithm is applied to simulate the transfer function of the imaging lens in the optical path and a phase grayscale image containing the wavefront information of the object light passing through the lens is prepared. Then, the incident parallel light field is modulated using two spatial light modulators to achieve wavefront reproduction of the light field passing through the lens. Finally, according to the imaging principle of the lens, a CCD is placed on the imaging surface of the two objects to obtain their tomography. The experimental results show that the stereoscopic tomographic image of the detected object is observed at a distance of 298.5 mm and 337.6 mm from the spatial light modulator when the focal length of the simulated lens is set to 150 mm and the calculated diffraction distance is 150 mm, respectively. The lateral magnifications of the two front and back imaging planes in the x and y axes are (1.1, 1.08) and (1.34, 1.09), respectively. Compared with the lateral magnification (1, 1.2) calculated by the lens imaging formula, these relative errors are (10.6%, 8%) and (11.7%, 8%). The angular spread is 2.95° and 2.61°, respectively, and the relative error is less than 5%, which confirms the experiment principals. The experiment provides an effective research method for the subsequent three-dimensional display and new holographic technology.