Colour facilities in hexagonal boron nitride (hBN) are promising candidates as quantum mild sources for future applied sciences. *
Within the article “Nanoscale resolved mapping of the dipole emission of hBN colour facilities with a scattering-type scanning near-field optical microscope “, Iris Niehues, Daniel Wigger, Korbinian Kaltenecker, Annika Klein-Hitpass , Philippe Roell, Aleksandra Ok. Dąbrowska, Katarzyna Ludwiczak, Piotr Tatarczak, Janne O. Becker , Robert Schmidt, Martin Schnell, Johannes Binder, Andrzej Wysmołek and Rainer Hillenbrand make the most of a scattering-type near-field optical microscope (s-SNOM) to check the photoluminescence (PL) emission traits of such quantum emitters in metalorganic vapor part epitaxy grown hBN. *
On the one hand, Iris Niehues et al. reveal direct near-field optical excitation and emission via interplay with the nanofocus of the AFM tip leading to a subdiffraction restricted tip-enhanced PL hotspot. *
Then again, the authors present that oblique excitation and emission by way of scattering from the AFM tip considerably will increase the recorded PL depth. This demonstrates that the tip-assisted PL (TAPL) course of effectively guides the generated mild to the detector. *
Iris Niehues et al. apply the TAPL technique to map the in-plane dipole orientations of the hBN colour facilities on the nanoscale. This work promotes the broadly out there s-SNOM method to purposes within the quantum area together with characterization and optical management. *
The investigation makes use of a scattering-type near-field optical microscope using a metallized Arrow AFM tip ( NanoWorld Arrow-NCPt AFM probe) illuminated by monochromatic laser mild. *
The AFM tip acts as an optical antenna, remodeling the incident p-polarizedlight right into a extremely targeted close to subject on the AFM tip apex, the so-called nanofocus. *
The nanofocus interacts with the pattern resulting in modified scattering from the AFM tip and encoding native pattern properties.
In standard s-SNOM operation, the elastically scattered mild is recorded as operate of pattern place (notice that the pattern is scanned), yielding near-field optical pictures with a spatial decision right down to 10 nm. *
To supress background scattering, the AFM is operated in tapping mode and the detector sign is demodulated at a better harmonic of the AFM tip’s oscillation frequency. *
Within the article, Iris Niehues et al. use the s-SNOM instrument to check PL from particular person hBN colour facilities. *
To that finish, the inelastically tip-scattered mild is recorded with a grating spectrometer coupled to a CCD digicam. Observe that sign demodulation has not been attainable with the usage of a CCD digicam to this point. It might be achieved using a photomultiplier tube or related. Importantly, the authors’ s-SNOM setup features a high-quality, silver-protected off-axis parabolic mirror with a numerical aperture (NA) of 0.72, which optimizes the focusing and assortment effectivity of the optical system and is essential for the carried out PL measurements. *
Characterization of photoluminescence mapping
Within the particular experiments carried out by “, Iris Niehues et al., the authors make use of the near-field optical microscope in tapping mode, with low oscillation amplitudes between 20 nm and 30 nm, to detect PL alerts influenced by the presence of the metallic AFM tip. *
They use normal metallic Arrow AFM suggestions (NanoWorld Arrow-NCPt) All through this examine, Iris Niehues et al., use a 532 nm (2.33 eV) laser for the optical excitation of the hBN colour facilities. *
Photoluminescence (PL) measurement of a single colour heart taken with an AFM tip. The photographs are proven with the identical colour bar for higher comparability of the noticed PL intensities. (a) PL depth map with out the tip exhibiting a diffraction restricted emission spot. (b) PL spectrum of the studied emitter recorded with an prolonged integration time contained in the arc in (c). The zero-phonon line (ZPL) and optical phonon sidebands (PSBs) of 160 meV are marked in addition to the broad background PL (black line). (c) PL map of the identical emitter with the AFM tip exhibiting two subdiffraction restrict options marked as “dot” and “arc.” (d) Lineprofiles alongside the dashed strains in (a) in black and (c) in crimson (darkish measurement, vibrant Gaussian suits). The fitted full widths at half most (FWHM) are 110 nm (dot), 209 nm (arc), and 1,418 nm (w/o tip). (e) Schematic of the interference between direct and oblique excitation/emission of the colour heart by way of the AFM tip (TAPL). Inset reveals the nanofocus interplay on the location of the colour heart explaining the dot (TEPL). (f) Analytical copy of the TAPL arc in (c) making use of the mannequin in (e).
*Iris Niehues, Daniel Wigger, Korbinian Kaltenecker, Annika Klein-Hitpass , Philippe Roell, Aleksandra Ok. Dąbrowska, Katarzyna Ludwiczak, Piotr Tatarczak, Janne O. Becker , Robert Schmidt, Martin Schnell, Johannes Binder, Andrzej Wysmołek and Rainer Hillenbrand
Nanoscale resolved mapping of the dipole emission of hBN colour facilities with a scattering-type scanning near-field optical microscope
Nanophotonics, vol. 14, no. 3, 2025, pp. 335-342
DOI: https://doi.org/10.1515/nanoph-2024-0554
Open Entry The article “Nanoscale resolved mapping of the dipole emission of hBN colour facilities with a scattering-type scanning near-field optical microscope” by Iris Niehues, Daniel Wigger, Korbinian Kaltenecker, Annika Klein-Hitpass , Philippe Roell, Aleksandra Ok. Dąbrowska, Katarzyna Ludwiczak, Piotr Tatarczak, Janne O. Becker , Robert Schmidt, Martin Schnell, Johannes Binder, Andrzej Wysmołek and Rainer Hillenbrand is licensed below a Inventive Commons Attribution 4.0 Worldwide License, which allows use, sharing, adaptation, distribution and copy in any medium or format, so long as you give acceptable credit score to the unique creator(s) and the supply, present a hyperlink to the Inventive Commons license, and point out if adjustments have been made. The photographs or different third occasion materials on this article are included within the article’s Inventive Commons license, except indicated in any other case in a credit score line to the fabric. If materials shouldn’t be included within the article’s Inventive Commons license and your supposed use shouldn’t be permitted by statutory regulation or exceeds the permitted use, you have to to acquire permission immediately from the copyright holder. To view a replica of this license, go to http://creativecommons.org/licenses/by/4.0/.
