Variable aperture with graded attenuation combined with adjustable focal length lens

In this paper, we demonstrate a variable aperture with graded attenuation combined with adjustable focal length lens actuated by hydraulic control. Two cylindrical chambers and a middle substrate are stacked to form the device body. An elastic film is fabricated in the middle substrate like a sandwich. In the initial state, the dyed liquid is fully covered on the elastic film. The variable aperture shows the state of the maximum optical attenuation. When the bottom chamber is injected with liquid, the elastic film can form a convex surface. The dyed liquid will be pushed to the side wall of the chamber by the raised elastic film and the optical attenuation can be varied by changing the volume of the injected liquid. The proposed device can achieve both the variable attenuator function and the variable-focus lens function. The experiments show that the variable aperture can obtain dynamic attenuation ranges from 33.01 dB to 0.71 dB, and the zoom liquid lens can reach 2.9☓magnifying power. The device can be applied in imaging systems and fiber-optic communications.