Large Angle Of Bragg Diffraction Using Interfrence Of Acoustic Wave Inside Acousto-Optic Deflector

The laser beam is often steered in different directions in a variety of laser-advanced microprocessing technologies, such as laser micromachining, laser patterning and laser selective-area doping. Scanners are traditionally used to direct the beam to different locations on the workpiece. The mechanical motion of x-y mirrors in such scanners affects the accuracy of beam positioning and repeatability in high precision manufacturing. Beam steering without any moving optical component is necessary to overcome the limitations of current scanning technology. Stationary optical devices such as acousto-optic modulators (AOM), acousto-optic deflectors (AOD) and acousto-optic tunable filters (AOTF) have widespread applications in the field of laser microfabrication for intensity modulation and laser beam steering. AODs are commonly used with continuous-wave lasers in laser direct writing systems to provide flexible and high-speed beam scanning with high precision and accuracy. A pair of AODs is mounted orthogonally to provide dual axis (x-y) laser scanning. The deflection scan angle, however, is small due to the finite distance between the two separate deflectors. This optical configuration can be simplified by realizing 2D AO interaction in a single AO crystal. This paper discusses an integrated AOD to allow compact construction and efficient operation with large deflection scan angle. This type of AODs would be useful for large-area processing with high throughput