Tunable liquid lens for three-photon excitation microscopy.

We demonstrate a novel electrowetting liquid combination using a room temperature ionic liquid (RTIL) and a nonpolar liquid, 1-phenyl-1-cyclohexene (PCH) suitable for focus-tunable 3-photon microscopy. We show that both liquids have over 90% transmission at 1300 nm over a 1.1 mm pathlength and an index of refraction contrast of 0.123. A lens using these liquids can be tuned from a contact angle of 133 to 48° with applied voltages of 0 and 60 V, respectively. Finally, a three-photon imaging system including an RTIL electrowetting lens was used to image a mouse brain slice. Axial scans taken with an electrowetting lens show excellent agreement with images acquired using a mechanically scanned objective.

Fabrication and characterization of a two-dimensional individually addressable electrowetting microlens array: erratum.

The authors present an erratum to update the Acknowledgements section in their published article, ["Fabrication and characterization of a two-dimensional individually addressable electrowetting microlens array," Opt. Express31, 30550 (2023)10.1364/OE.497992].

Fabrication and characterization of a two-dimensional individually addressable electrowetting microlens array.

We demonstrate a two-dimensional, individually tunable electrowetting microlens array fabricated using standard microfabrication techniques. Each lens in our array has a large range of focal tunability from -1.7 mm to -∞ in the diverging regime, which we verify experimentally from 0 to 75 V for a device coated in Parylene C. Additionally, each lens can be actuated to within 1% of their steady-state value within 1.5 ms. To justify the use of our device in a phase-sensitive optical system, we measure the wavefront of a beam passing through the center of a single lens in our device over the actuation range and show that these devices have a surface quality comparable to static microlens arrays. The large range of tunability, fast response time, and excellent surface quality of these devices open the door to potential applications in compact optical imaging systems, transmissive wavefront shaping, and beam steering.

Adaptive aberration correction using an electrowetting array.

We demonstrate a method that permits wavefront aberration correction using an array of electrowetting prisms. A fixed high fill factor microlens array followed by a lower fill factor adaptive electrowetting prism array is used to correct wavefront aberration. The design and simulation of such aberration correction mechanism is described. Our results show significant improvement to the Strehl ratio by using our aberration correction scheme which results in diffraction limited performance. Compactness and effectiveness of our design can be implemented in many applications that require aberration correction, such as microscopy and consumer electronics.