Nanoresonators fabricated from low-loss dielectrics with second-order nonlinearity have emerged as a widespread platform for nonlinear frequency conversion at the nanoscale. However, persisting challenge in this research is generated complex far-field polarization state of upconverted light, which limiting factor many applications. It will be highly desirable to generate uniform states across a...

We will establish far eld identities for the scattering of time-harmonic acoustic waves from sound-soft and sound-hard obstacles and will illustrate two applications of these identities for the inverse obstacle scattering problem. Firstly, we will provide an alternate proof for the Fr echet diierentiability of the far eld pattern with respect to the boundary. Secondly, we will connect the ident...

In this paper I investigate the dynamics of vortex patches in the Yudovitch phase space. I derive an approximation for the evolution of the vorticity in the case of nested vortex patches with distant boundaries, and study its long-time behaviour.

We demonstrate two-color fluorescence microscopy with nanoscale spatial resolution by applying stimulated emission depletion on fluorophores differing in their absorption and emission spectra. Green- and red-emitting fluorophores are selectively excited and quenched using dedicated beam pairs. The stimulated emission depletion beams deliver a lateral resolution of <30 nm and 65 nm for the green...

In far-field speech recognition systems, training acoustic models with alignments generated from parallel close-talk microphone data provides significant improvements. However it is not practical to assume the availability of large corpora of parallel close-talk microphone data, for training. In this paper we explore methods to reduce the performance gap between far-field ASR systems trained wi...

Plasmonics and near-field optical nanoscopy both deal with expanding optics into the subwavelength regime. However, these two fields have so far followed parallel paths of development and only recently have researchers started to explore combinations of their concepts with potential synergy. In this Perspective, we provide an up-to-date summary of the successful combinations reported and give i...