Electrowetting-actuated optofluidic phase modulator

Three-phase electrowetting liquid lens with deformable liquid iris

Inspired by the arrangement of iris and crystalline lens in human eyes, we propose a three-phase electrowetting liquid lens with a deformable liquid iris (TELL-DLI). The proposed electrowetting liquid lens has three-phase fluid: air, conductive liquid, and dyed insulating liquid. The insulating liquid is distributed on the inner wall of the chamber in a ring shape. By applying voltage, the contact angle is changed, so that the dyed insulating liquid contracts towards the center, which is similar to the contraction of iris and the function of crystalline lens muscle in human eyes. The variation range of focal length is from -451.9 mm to -107.9 mm. The variation range of the aperture is from 4.89 mm to 0.6 mm. Under the step voltage of 200 V, the TELL-DLI can be switched between the maximum aperture state and the zero aperture state, and the switching time is ∼150/200 ms. Because of the discrete electrodes, TELL-DLI can regionally control the shape and position of the iris, and switch between circle, ellipse, sector, and strip. The TELL-DLI has a wide application prospect in imaging systems, such as microscopic imaging system, and has the potential to be applied in the field of complex beam navigation.

Design, fabrication, and characterization of an optofluidic phase modulator array based on the piezoelectric effect

In this paper, an optofluidic phase modulator array based on the piezoelectric effect is designed, fabricated, and characterized. This array is composed of three piezoelectric ceramics arranged on the vertices of an equilateral triangle. A transparent liquid fills the inner cavity of the ceramics. Due to the inverse piezoelectric effect, the length of the transparent liquid is changed at different voltages, which contributes to the optical phase modulation. According to experiment results, it is found that our modulator arrays exert continuous optical phase adjustment ability. When the voltage ranges from 0 to 135 V, the relative length variation reaches up to 9.286 µm, and consequently our proposed modulator arrays perform about 9.685 π optical phase modulation.

High stability liquid lens with optical path modulation function

In this paper, a high stability liquid lens with optical path modulation function is designed and fabricated. The liquid lens has an outer chamber and an inner chamber, and the inner chamber has a structure with three annular anchoring layers. This structure can limit the sliding of the three-phase contact line under electrowetting effect and anchor the position of contact angle with a limited distance. The feasibility of this structure is verified by simulation and practice. The zoom imaging, contact angle, focal length and response time of the liquid lens are analyzed. The structure with three annular anchoring layers provides six anchored precision optical path modulation gears, and the optical path difference can be changed by mechanical hydraulic control, up to 1.17 mm. Widespread applications of the proposed liquid lens are foreseeable such as microscopic imaging and a telescope system, etc.