Electrowetting-actuated optofluidic phase modulator

Abstract

In this paper, an optofluidic phase modulator based on electrowetting is presented. The modulator consists of an inner and outer chamber. Two immiscible liquids are filled into the chambers, and a transparent sheet is fixed between the liquid-liquid interface to obtain a flat interface. By applying different voltages to the modulator, the flat interface moves up and down leading to the change of optical path length. Consequently, the variation of the optical path in the proposed modulator exploits the ability to alter the optical phase. To prove the concept, a prototype of the phase modulator is fabricated in experiment, and the ability of phase modulation is detected. Our proposed modulator performs optical phase shift up to ∼6.68 π driven with 150 V. Widespread applications of such an optofluidic phase modulator is foreseeable.

Non-aqueous organic solution based on a large-aperture spherical electrowetting liquid lens with a wide tunable focal length range

“…33,36,47 The non-aqueous system is completely a compound of a nonaqueous organic solvent, and the solute usually contains some special organic electrolytes. 48,49 At present, almost all the conductive liquids used in electrowetting liquid lenses contain water, and most of them are aqueous solutions. [36][37][38][39][40][41][42][43][44][45][46] A few studies use other polar solutions, such as ethylene glycol, propylene glycol, propylene carbonate, etc.…”

“…Sometimes some electrolytes are added to improve the conductivity of the conductive liquid. [48][49][50] Non-aqueous conductive liquids also contain ionic liquids, but they are more viscous and have the potential to mix with oil phases. [51][52][53][54][55] However, the existence of water in the conductive liquid inevitably implies the problem of evaporation, hydrolysis bubbles, or the tendency toward a higher freezing point.…”

Effect of frequency on droplet actuation in reverse electrowetting

“…In recent years, reverse electrowetting technology (REW) has attracted people's attention. In 2020, Zhang et al [17] proposed a REW-based phase modulator with 6.68π optical phase modulation. In the same year, Liang et al [18] developed a REW liquid lens, whose focal length ranged from 87.153 mm * Author to whom any correspondence should be addressed.…”