The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Recently, the concept of the geometric Pancharatnam-Berry (P-B) phase has been successfully extended to optical metasurfaces operating in the nonlinear regime1–3. It was shown that the nonlinear geometric P-B phase of each meta-atom is determined by the spin of the fundamental wave, the spin of the nonlinear signal, and the order of the nonlinear process1. By manipulating the interferences of SHG...
We report highly-nonlinear ultrathin metasurfaces based on coupling of plasmonic nanoresonators with intersubband nonlinearities. Nonlinear susceptibilities over 1×106 pm/V and conversion efficiencies ∼0.1% were measured for second harmonic generation in mid-infrared for 10 kW/cm2 input intensity. Complete phase control of local nonlinear response is demonstrated.
We report highly-nonlinear metasurfaces based on combining electromagnetically-engineered plasmonic nanoresonators with quantum-engineered intersubband nonlinearities. Experimentally, effective nonlinear susceptibility over 480 nm/V was measured for second-harmonic generation at normal incidence.
We demonstrate enhancement of second-harmonic generation efficiency in sub-wavelength resonant nanostructures supporting optically induced magnetic response. This is achieved through simultaneous excitation of electric and magnetic multipoles at the second-harmonic wavelength and their constructive interference.
We report highly-nonlinear metasurfaces based on coupling of electromagnetically-engineered plasmonic nanoresonators with quantum-engineered intersubband nonlinearities. Experimentally, effective nonlinear susceptibility over 50 nm/V was measured for second-harmonic generation under normal incidence.
Optical antennas convert propagating far-field radiation into localized near-fields [1]. Perhaps the simplest optical antenna is a sharp metal tip, which is commonly utilized in near-field microscopy and spectroscopy [1,2]. Usually, the coupling of far-field light to the near-field requires either a field polarized along the tip axis (longitudinal field) [2] or a surface grating on the tip [3]. Here,...
We report third-harmonic generation in graphene on glass. Polarization and azimuthal-rotation data confirm graphene's isotropic symmetry properties. High-contrast imaging yields structural features and its coherent nature via layer-number dependence.
Polarization Second Harmonic Generation enables to quantify some of the underlying molecular details of key biological structures within muscle, axons and collagen at suboptical scales. However, it is only available in dedicated labs. In this work we detail a procedure to adapt and calibrate a commercial multiphoton microscope (Leica TCS-SP5) to acquire PSHG images reliably. For this, two different...
Shape and size resonant plasmonic enhancement of Second Harmonic Generation (SHG) from individual and coupled nanoholes in thin metal films is studied, and giant signals are observed from individual hot spots.
Collagen is the major protein of the extracellular matrix and plays a central role in the formation of fibrillar and microfibrillar networks, basement membranes, as well as other structures of the connective tissue. As a fundamental brick of the architecture of tissues, it guarantees organs functioning and is crucial in the adaptative response to various tissue injuries. This protein is characterized...
This paper presents the growth, optical characterization, and dielectrophoretic response of lithium niobate (LiNbO3) nanowires. These nanosize wires demonstrate similar optical characteristics as their bulk counterparts and may be utilized as second-harmonic radiating imaging probes (SHRIMPs), or manipulated using electric fields to orient them in a preferable direction. LiNbO3 nanowires are prepared...
We propose new second-harmonic-generation probes of surface chirality, based on circular polarizations or handed superpositions of radial and azimuthal polarizations. Because of normal incidence focusing, the techniques are not sensitive to anisotropy.
The noncentrosymmetric molecular structures responsible for the second order nonlinear effects of collagen fibrils are identified by sum frequency vibrational spectroscopy. CH2 and C=O functional groups dominate the achiral and chiral spectra, respectively.
Two experimental geometries are introduced to selectively image transverse and longitudinal components of the optical near-field in plasmonic nanostructures. Our experimental results are in excellent agreement with theoretical predictions.
The orientation and different levels of crystallization in biological nanostructures are revealed by polarization dependent studies under SHG and THG microscopies.
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.