Holographic femtosecond laser processing and three-dimensional recording in biological tissues

Data recording on biological tissues and prostheses with femtosecond laser processing for personal identification is demonstrated. The target materials axe human fingernails (fingernail memory) and dental prostheses (dental memory). Because they have unexpected movements and individual three-dimensional shapes, the processing system is required an adaptive focusing and high-throughput recording capability. The adaptive focusing is performed with a target surface detection. The high throughput is realized by parallel laser processing based on a computer-generated hologram displayed on a spatial light modulator. Two-dimensional and three-dimensional parallel laser processing of glass is demonstrated.