Sparse-exposure technique in holographic two-photon polymerization

Holographic two-photon polymerization is based on a high-speed, low-loss parallel laser irradiation technique inside photosensitive materials using a computer-generated hologram displayed on a liquid crystal spatial light modulator. We demonstrated a sparse exposure technique combining parallel exposure and scanning exposure to improve the fabrication throughput and to achieve simultaneous fabrication of linear structures with different widths. We also demonstrated fabrication of space-variant structures by changing a CGH, as well as parallel fabrication of voxel structures with single femtosecond laser pulse irradiation.