Por Giorgio Volpe (Department of Chemistry, University College London, London, United Kingdom).

Colloidal self-assembly has been investigated as a promising approach for the fabrication of photonic materials and devices to make, e.g., coatings, displays, and sensors for diagnostics. The final optical properties of such materials strongly depend on the interactions among the constituent colloids and on their reciprocal spatial arrangement. Randomly distributed colloids can be employed to fabricate robust lasing systems where laser action is obtained thanks to the multiple scattering of light within the colloidal material. Here, I will show the self-organization of programmable random lasers from the reversible out-of-equilibrium self-assembly of colloids. Under an external light stimulus, these laser systems self-assemble, are responsive and show dynamic properties, such as the possibility of reconfiguring their structure and their lasing properties in space and time. These man-made lasers with their life-like features (responsiveness, reconfigurability and cooperation) are a first step towards the realization of fully animate lasers capable of independent motion and autonomous adaptation in response to external stimuli.

Reference: M. Trivedi et al., Self-organized lasers from reconfigurable colloidal assemblies, Nature Physics 18, 939-944 (2022).