Optical system for 3d printing and control method thereof

An optical system for 3D printing, comprising a laser device (1), a beam expanding system (2), a beam splitter (3), a spatial light modulator (4) and a focusing system (5), characterized in that the spatial light modulator (4) is connected with a computer for generating a target modulation pattern and configured to generate a modulation pattern after receiving the target modulation pattern generated by the computer;

• a light beam emitted by the laser device (1) is expanded into a parallel light beam having a large diameter by the beam expanding system (2) and then irradiates on the beam splitter (3);
• a part of the expanded light beam reaches the spatial light modulator (4) for modulation after passing through the beam splitter (3), then the modulated light beam is reflected to the beam splitter (3), and a part of the modulated light beam is focused by the focusing system (5) and then irradiates on a target plane (6) for 3D printing.