Reversible photothermal tuning of a salty water microdroplet

Abstract

A fully reversible photothermal tuning of an inorganic salt (NaCl)-water microdroplet standing on a superhydrophobic surface is demonstrated. The size change of the microdroplet is caused by a focused infrared laser beam in a humidity-controlled chamber and a fully reversible large spectral tuning up to approximately 40 nm is achieved. The evaporation and growth of the microdroplet are modeled using a lumped system formulation of mass and energy conservations and a good agreement is observed between the experimental and theoretical results.

Spectral tuning of lasing emission from optofluidic droplet microlasers using optical stretching

“…Tunability of shape, size, and composition is an important advantage of reconfigurable optofluidic components based on microdroplets. The most straightforward way of tuning spectral position of WGMs of airborne droplets relies on controlled changes of the liquid cavity size using evaporation/condensation [8], electrowetting [9], or photothermal effect [10]. Adjustment of resonant frequency of microdroplet optical cavity can also be achieved by controlled deformation of the microdroplet which lifts the degeneracy of WGMs with different azimuthal mode numbers.…”

Latest achievements in generalized Lorenz‐Mie theories: A commented reference database

“…, and Kiraz et al . already previously quoted in the section devoted to internal fields. It is here worthwhile to mention that thermal lenses have been also extensively studied in another context, the one of nonlinear dynamical theory and associated experiments, e.g.…”

“…From the same group, Kiraz et al . similarly dealt with reversible photothermal tuning of a salty water microdroplet.…”

Temperature-induced tuning of emission spectra of liquid-crystal optical microcavities

“…8,9 Thus, such microdroplets represent attractive self-assembled optofluidic cavities providing large flexibility in adjusting their optical properties, shape, and/or size which in turn allows for straightforward tuning of the cavity resonant spectrum. [10][11][12][13][14] Liquid crystals (LCs) are complex fluids combining long-range organization found in crystalline solids with liquid-like fluidity that opens up the possibility of controlling the molecular orientation. In general, organization of LC molecules in any given state is characterized by the orientation of the molecular director field.…”