Thermocapillary manipulation of liquid optical waveguides

Project Description

The overall goal of this project is to explore how light can be guided and manipulated inside a thin liquid film, turning it into an optical waveguide with real-time dynamic control over its functionality.

If a liquid film is suspended within an immiscible liquid environment, it will maintain uniform and smooth surfaces preventing branching of light that is typically observed in soap films. By prescribing a non-uniform temperature distribution on the surface of the suspended film, one can control its local thickness via the thermocapillary effect which is the variation of a liquid’s surface tension with temperature. This may allow to create liquid channels within the film, guiding the light in any desired path. By changing the prescribed temperature in real time, one can continuously bend and move the liquid channels, resulting in a programmable liquid film optical waveguide. In this project, the REU student will design, fabricate, and test such a proof-of-concept experiment that manipulates a single beam of light inside a liquid film.

 Mentors

Valeri Frumkin, PI Jacob Garrett Ryan Engle

• Design and model a 3D frame the will support a liquid film in an aqueous environment and couple it to an optical fiber
• Design a simple array of heating elements that will couple to the frame and generate a desired temperature profile in the liquid film
• Fabricate both designs using 3D printing and other fabrication resources
• Preform measurements of the deflection of a light beam inside the liquid film by the induced temperature field
• Learning about surface tension, wetting, thermocapillarity, and light propagation through different mediums
• 3D design and modelling
• Fabrication by means of additive manufacturing, and other related techniques
• Learning to take optical measurements and analyze the acquired data

Timeline