Nuove tecnologie per studiare il cervello con la luce

Nell'ultimo decennio l'optogenetica è diventata una delle tecniche più utilizzate nelle neuroscience moderne. Attraverso l'espressione di proteine fotosensibili in specifiche classi di neuroni, è possibile controllare otticamente l'attività neuronale, attivando o inibendo la generazione di segnali cerebrali. Tuttavia, il cervello è un tessuto intrinsecamente dispersivo, e per sfruttare al meglio le potenzialità dell'optogenetica la comunità scientifica ha sviluppato una serie di approcci in grado di portare efficientemente la radiazione luminosa nel cervello. Questo lavoro ha lo scopo di analizzare lo stato dell'arte dei dispositivi impiantabili per esperimenti di optogenetica, concentrandosi sul ruolo ricoperto dalle micro e nanotecnologie

Non‐Blinking Single‐Photon Generation with Anisotropic Colloidal Nanocrystals: Towards Room‐Temperature, Efficient, Colloidal Quantum Sources

Blinking and single-photon emission can be tailored in CdSe/CdS core/shell colloidal dot-in-rods. By increasing the shell thickness it is possible to obtain almost non-blinking nanocrystals, while the shell length can be used to control single-photon emission probability

High-Purcell-factor dipolelike modes at visible wavelengths in H1 photonic crystal cavity

The optimization of H1 photonic crystal cavities for applications in the visible spectral range is reported, with the goal to obtain a versatile photonic platform to explore strongly and weakly coupled systems. The resonators have been realized in silicon nitride and weakly coupled to both organic (fluorophores) and inorganic (colloidal nanocrystals) nanoparticles emitting in the visible spectral range. The theoretical Purcell factor of the two dipolelike modes in the defect has been increased up to approximately 90, and the experimental quality factor was measured to be approximately 750

Single colloidal quantum dots as sources of single photons for quantum cryptography

Colloidal nanocrystals, i.e. quantum dots synthesized trough wet-chemistry approaches, are promising nanoparticles for photonic applications and, remarkably, their quantum nature makes them very promising for single photon emission at room temperature. In this work we describe two approaches to engineer the emission properties of these nanoemitters in terms of radiative lifetime and photon polarization, drawing a viable strategy for their exploitation as room-temperature single photon sources for quantum information and quantum telecommunications