Combination of scanning probe technology with photonic nanojets

• Published in: Scientific reports Vol. 7; no. 1; pp. 3474 - 7
• Main Authors: Duocastella, Martí, Tantussi, Francesco, Haddadpour, Ali, Zaccaria, Remo Proietti, Jacassi, Andrea, Veronis, Georgios, Diaspro, Alberto, Angelis, Francesco De
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 14.06.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 639/624/1107/328; 639/925/930/2735; Atomic force microscopy; Data processing; Fabrication; Humanities and Social Sciences; Image processing; Microscopes; multidisciplinary; Raman spectroscopy; Science; Science (multidisciplinary); Spatial discrimination; Spectroscopy
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-03726-5

Light focusing through a microbead leads to the formation of a photonic nanojet functional for enhancing the spatial resolution of traditional optical systems. Despite numerous works that prove this phenomenon, a method to appropriately translate the nanojet on top of a region of interest is still missing. Here, by using advanced 3D fabrication techniques we integrated a microbead on an AFM cantilever thus realizing a system to efficiently position nanojets. This fabrication approach is robust and can be exploited in a myriad of applications, ranging from microscopy to Raman spectroscopy. We demonstrate the potential of portable nanojets by imaging different sub-wavelength structures. Thanks to the achieved portability, we were able to perform a detailed optical characterization of the resolution enhancement induced by the microbead, which sheds light into the many contradictory resolution claims present in literature. Our conclusions are strongly supported by rigorous data analysis and by numerical simulations, all in perfect agreement with experimental results.