Electrowetting-based beam deflection controller in three-dimension

In this paper, an electrowetting-based prism-arrays system is proposed to be non-mechanical beam deflection controller in the three-dimensional space. The system is composed of five liquid prism units arranged at equal intervals in a cross shape. The relationship between beam deflection angle, electrowetting contact angle, and liquid refractive index are derived. The influence of electrowetting saturation, liquid refractive index, and interval between adjacent prisms on the performance of prism-arrays system are simulated in COMSOL, where the length and width of each prism are set to 3mm, and the height is set to 6mm. The shape of the liquid interface in liquid prism and its deflection are analyzed. The results show that the system succeed to achieve continuous control of beam deflection within a certain range, and the beam deflection angle of this arrayed liquid prisms is from -20° to 20° when 1-chloronaphthalene oil and 1% Nacl aqueous solution with sodium benzoate are filled in the liquid prisms. The smaller interval between adjacent prisms can increase the beam control range of the system. However, the liquid prism unit has a certain size, so the interval cannot be infinitely small. As the interval is set to 9mm, the steering region of the prism-arrays system is in a conical region with an apex angle of 40°, and the vertex of the circular cone is located at the 22.05mm in the z-axis. The proposed system will promote the development of nonmechanical beam deflection technology and have a wide range of applications.