Direct Laser Writing of Computer-Generated Holograms by Photodissolution of Silver in Arsenic Trisulfide

Abstract

Photodissolution is a process that is well known for its ability to cause inclusion of silver into the matrix of a chalcogenide layer, changing its optical properties. In this paper, using e-beam deposition, we developed Ag (74 nm)/As2S3 (355 nm) bilayers and characterized the photodissolution kinetics when exposed to actinic radiation. We showed that local complete silver photodissolution at the micron scale can be achieved. Based on this result, we then developed amplitude-based computer-generated holograms using direct laser writing. CW lasers with beam shaping and short pulse lasers with beam scanning were both implemented. Elements with 8.5 µm and <1 µm spatial resolution and close to theoretical intensity distribution, respectively, were successfully demonstrated.

Keywords

• chalcogenides
• photodissolution
• computer-generated holograms
• e-beam deposition