P De Santis

Bio: P De Santis is an academic researcher. The author has contributed to research in topics: Image resolution & Diffraction. The author has an hindex of 1, co-authored 1 publications receiving 7 citations.

Two-point resolution with antiphase coherent illumination. I. One-dimensional systems

Abstract: The limit of resolution for two antiphase coherent point objects is studied with reference to one-dimensional diffraction limited optical systems (slit apertures). The ratios of measurable to real point separation and of measurable to real peak intensity are also investigated.

Quantum Fisher information with coherence

Abstract: In recent proposals for achieving optical super-resolution, variants of the quantum Fisher information (QFI) quantify the attainable precision. We find that claims about a strong enhancement of the resolution resulting from coherence effects are questionable because they refer to very small subsets of the data without proper normalization. When the QFI is normalized, accounting for the strength of the signal, there is no advantage of coherent sources over incoherent ones. Our findings have a bearing on further studies of the achievable precision of optical instruments.

Exploring the ultimate limits: super-resolution enhanced by partial coherence.

Abstract: The resolution of separation of two elementary signals forming a partially coherent superposition, defined by quantum Fisher information and normalized with respect to detection probabilities, is always limited by the resolution of incoherent mixtures. However, when the partially coherent superpositions are prepared in a controlled way, the precision can be enhanced by up to several orders of magnitude above this limit. Coherence also allows the sorting of information about various parameters into distinct channels as demonstrated by the parameter of separation linked with the anti-phase superposition and the centroid position linked with the in-phase superposition.

Apodization for improving the two-point resolution of coherent optical systems with defect of focus

Abstract: An amplitude apodization influenced defocused optical system used to form a coherent light illuminated two-point sources with an improved resolution is analyzed. The composite coherent image intensity distributions in the defocused and the Gaussian (Yd = 0) planes have been calculated and compared. It has shown the resolution of the apodized optical system is significantly increased for an excessive amount of defocusing effect. As is clearly evidenced by the presence of irradiance dip in the resulting intensity profiles can describe the super-two-point resolution phenomena in a maximum defocused plane (Yd = 2π).

Dark-field imaging as a non-invasive method for characterization of whispering gallery modes in microdisk cavities

Abstract: Whispering gallery mode microdisk cavities fabricated by direct laser writing are studied using dark-field imaging and spectroscopy in the visible spectral range. {Dark-field imaging allows us to directly visualize the spatial intensity distribution of whispering gallery modes. We extract their azimuthal and radial mode indices from dark-field images, and find the axial mode number from the dispersion relation. The scattering spectrum obtained in the confocal arrangement provides information on the density of optical states in the resonator. The proposed technique is a simple non-invasive way to characterize the optical properties of microdisk cavities.