Droplet Lasers for Smart Photonic Labels

Abstract

Microscopic lasers represent a promising tool for the development of cutting-edge photonic devices thanks to their ability to enhance light–matter interaction at the microscale. In this work, we realize liquid microlasers with tunable emission by exploiting the self-formation of three-dimensional liquid droplets into a polymeric matrix driven by viscoelastic dewetting. We design a flexible device to be used as a smart photonic label which is detachable and reusable on various types of substrates such as paper or fabric. The innovative lasing emission mechanism proposed here is based on whispering gallery mode emission coupled to random lasing, the latter prompted by the inclusion of dielectric compounds into the active gain medium. The wide possibility of modulating the emission wavelength of the microlasers by acting on different parameters, such as the cavity size, type and volume fraction of the dielectrics, and gain medium, offers a multitude of spectroscopic encoding schemes for the realization of photonic barcodes and labels to be employed in anticounterfeiting applications and multiplexed bioassays.

Microcavity- and Microlaser-Based Optical Barcoding: A Review of Encoding Techniques and Applications

“…A smart photonic label containing liquid droplet microcavities was reported, which can be attached to different kinds of substrates such as paper and fabric (Figure 10d). 115 The dyedoped droplets with diameters in the range 100−1000 μm were encapsulated into a polydimethylsiloxane (PDMS) matrix. Whispering-gallery-mode lasing as well as random lasing (by the addition of scattering TiO 2 micropowder) were demonstrated.…”

“…Copyright (2020) The Author(s). (d,e) Reproduced with permission from ref . Copyright (2021) American Chemical Society.…”

Plasmonic Refractive Index Sensor Enhanced with Chitosan/Au Bilayer Thin Film for Dopamine Detection

“…The essential component of the kit developed by Yue and co-workers was a self-assembled silica microsphere decorated with the SARS-CoV-2 virus’s nucleocapsid proteins (N-proteins). The detection limits for N-protein antibody immunoglobulin (N-IgG) and immunoglobulin M (N-IgM) were determined to be 1 µg/mL and 2 µg/mL, respectively [ 30 ]. In addition, photonic crystals composed of alternating regions of high and low dielectric constants with 1D, 2D, or 3D periodic array arrangements have been used as sensors due to their well-defined physical properties and the presence of energy bands [ 31 , 32 , 33 , 34 ].…”

Optofluidic devices with programmable and responsive functions

“…Finally, an AI authentication system was built to distinguish true/fake information from optical anticounterfeiting systems. Benefiting from the multileveled anticounterfeiting systems, Figure 6.155 illustrates the potential applications which could be applied to physical unclonable functions for valuable goods, secure communication, 242 healthcare settings, cybersecurity, E-commerce, and finance. 248 To validate the coding capacity, each pixel on the ring pattern can be converted onto a CIE map with infinite color combination and capacity.…”

“…192,193,195,[238][239][240][241] By taking advantage of emission properties of luminescent materials, security labels with rapid readability and rich anticounterfeiting features have been proposed, including lasing signal, photonics barcodes, and luminescence images. 87,208,212,[242][243][244][245][246][247][248] To enhance the security level of optical encryption systems, multi-level optical security tags based on PL patterns have been developed to facilitate authentication. [249][250][251][252] For instance, security labels combining macroscopic patterns and microscale unclonable features have been proposed, where different scales would provide different information.…”