Optimization of metallic nanoapertures at short-wave infrared wavelengths for self-induced back-action trapping

Plasmonic nano-optical trap stiffness measurements and design optimization

“…The double nanohole (DNH) design is summarized on Fig. 1b, and is defined by the aperture diameter D, the gap size G between the gold apex and the gap width W 24 . We directly mill the DNH apertures by gallium-based focused ion beam (FEI dual beam DB235 Strata) into a 100 nm thick gold layer with a 5…”

“…Plasmonic nanostructures can generate intense electromagnetic field gradients over subwavelength dimensions, 1 allowing to trap nano-objects that would otherwise be too small or too transparent to be manipulated using conventional diffraction-limited optical tweezers [2][3][4][5][6] . Plasmonic nano-optical tweezers have emerged as a key enabling technology to trap nanoparticles [7][8][9][10][11][12][13] , quantum dots 14,15 , and proteins [16][17][18][19] using various plasmonic designs such as single apertures 3 , double nanohole apertures 5,20,21 , bowtie structures [22][23][24] , coaxial apertures 25,26 or dimer block antennas 27,28 .…”

“…A limitation is of course that the trapped object must be fluorescent and of size smaller than the gap G, but for calibration and design optimization purposes there is a wide range of fluorescent nano-objects commercially available. To demonstrate the effectiveness of this approach, we characterize plasmonic nano-tweezers based on double nanohole (DNH) apertures, which have received a large interest for plasmonic trapping 5,7,9,16,17,20,21,24,33 . We report the influence of the DNH geometry parameters directly on the experimental trap stiffness.…”

Metal Nanoapertures and Single Emitters

“…Resonant enhancement in a bow-tie or double-nanohole aperture can be achieved by variations in the aperture size and gap. [45] Machine learning has been applied to enhance the local field in a double-nanohole aperture by more than double by shaping. [46] Rate enhancement in plasmonic structures for single photon sources have been considered comprehensively elsewhere, [47] as well as the specific case of an aperture and a single emitter.…”

“…Resonant enhancement in a bow‐tie or double‐nanohole aperture can be achieved by variations in the aperture size and gap. [ 45 ] Machine learning has been applied to enhance the local field in a double‐nanohole aperture by more than double by shaping. [ 46 ]…”