Self-mixing interferometry and near-field nanoscopy in quantum cascade random lasers at terahertz frequencies
| Autor: | Reichel Kimberly S., Pogna Eva Arianna Aurelia, Biasco Simone, Viti Leonardo, Di Gaspare Alessandra, Beere Harvey E., Ritchie David A., Vitiello Miriam S. |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Nanophotonics, Vol 10, Iss 5, Pp 1495-1503 (2021) |
| Druh dokumentu: | article |
| ISSN: | 2192-8606 2192-8614 2020-0609 |
| DOI: | 10.1515/nanoph-2020-0609 |
| Popis: | We demonstrate that electrically pumped random laser resonators, operating at terahertz (THz) frequencies, and comprising a quantum cascade laser heterostructure, can operate as sensitive photodetectors through the self-mixing effect. We devise two-dimensional cavities exploiting a disordered arrangement of surface holes that simultaneously provide optical feedback and allow light out-coupling. By reflecting the emitted light back onto the surface with random holes pattern, and by varying the external cavity length, we capture the temporal dependence of the laser voltage, collecting a rich sequence of interference fringes that follow the bias-dependent spectral emission of the laser structure. This provides a visible signature of the random laser sensitivity to the self-mixing effect, under different feedback regimes. The latter effect is then exploited, in the near-field, to demonstrate detectorless scattering near-field optical microscopy with nanoscale (120 nm) spatial resolution. The achieved results open up possibilities of detectorless speckle-free nano-imaging and quantum sensing applications across the far-infrared. |
| Databáze: | Directory of Open Access Journals |
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