Two-dimensional acousto-optic deflector using on-axis anisotropic Bragg diffraction for internal drum scanning exposure systems

Abstract

We researched and demonstrated two-dimensional (2-D) deflectors constructed by on-axis type acousto-optic deflectors (AOD) in order to attain a multibeam recording for an internal drum scanning exposure system. First, we researched an on-axis AOD using anisotropic Bragg diffraction to obtain high diffraction efficiency. A significant improvement of diffraction efficiency was observed when acoustic waves are travelling in the [110] axis of paratellurite (TeO2) crystal, an incident light of linear polarization is traveling into a TeO2 along the [001] optic axis, the crystal is rotated about the [110] axis, and furthermore the direction of polarization of incident light is adjusted to the eigenmode of a TeO2 crystal. Second, we configured 2-D deflectors by cascading two AODs and achieved the multibeam laser recording for the internal drum scanning exposure system.