6533b7dcfe1ef96bd1272188

RESEARCH PRODUCT

Dielectric metalenses with engineered point spread function

Davood FathiMahdieh HashemiCarlos J. Zapata-rodríguezMohammad Mahdi Shanei

subject

Physicsbusiness.industry02 engineering and technology021001 nanoscience & nanotechnology01 natural sciencesRayAtomic and Molecular Physics and OpticsWavelengthFull width at half maximumAmplitudeOpticsApodizationModulationSide lobeElectric field0103 physical sciencesOptoelectronicsElectrical and Electronic Engineering010306 general physics0210 nano-technologybusinessEngineering (miscellaneous)

description

High-index silicon nanoblocks support excitation of both electric and magnetic resonance modes at telecommunication wavelengths. At frequencies where both electric and magnetic resonance modes are excited simultaneously, changing the geometrical dimensions of the silicon cubes creates a 2π full span over the phase of the transmitted light in different amplitude ranges. We take advantage of the additional power-flux modulation of the scattered signal to focus the incident light with desired full width at half maximum (FWHM) and side lobe levels (SLLs) in both the lateral and axial directions. By implementing proper amplitude filters within the telecommunication working wavelength (1.55 μm), a FWHM less than half of the wavelength (0.42λeff) and apodization with nearly faded SLLs are achievable. Our approach introduced in this paper provides a new way to design high efficiency metalenses with desired FWHM and SLL of focal spot.

https://doi.org/10.1364/ao.56.008917