Polarization tomography of metallic nanohole arrays

We report polarization tomography experiments on metallic nanohole arrays with square and hexagonal symmetry. As a main result, we find that a fully polarized input beam is partly depolarized after transmission through a nanohole array. This loss of polarization coherence is found to be anisotropic, i.e. it depends on the polarization state of the input beam. The depolarization is ascribed to a combination of two factors: i) the nonlocal response of the array due to surface plasmon propagation, ii) the non-plane wave nature of a practical input beam.Comment: 4 pages, 3 figures, 1 table, submitted to PR

Toxic effects of phenothiazines on the eye

Publications about the retinotoxic action of phenothiazine derivatives led the author to undertake an ophthalmological investigation in two psychiatric hospitals in The Netherlands. The pharmacological actions of phenothiazine preparations are listed and a survey of the phenothiazine derivatives which are at present in use is given. Some retinotoxic substances are discussed and a survey is given of the literature on the ocular complications of phenothiazine therapy. The eyes of 561 patients were examined. of whom 541 are included in this study. 343 of these patients(63.4 %) were found to have retinopathy. The correlation between the retinopathy and the total dose of phenothiazine preparations taken. and between the retinopathy and the duration of treatment. was highly significant. The correlation between the retinopathy and the average daily dose taken was significant. The retinopathy was associated with a reduced standing potential of the eye. as determined by electro-oculography. It was possibly responsible for diminished visual acuity in some cases, and for an abnormally large proportion of protans in the group of patients with colour defects. It was not possible to ascribe a more severe retinotoxic action to one or more specific phenothiazine derivatives than to others. In the author's opinion regular examination of the eyes of patients who are being treated with phenothiazine preparations in high dosage and for for a long period of time is indicated

Roles of secondary electrons and sputtered atoms in ion-beam-induced deposition

The authors report the results of investigating two models for ion-beam-induced deposition (IBID). These models describe IBID in terms of the impact of secondary electrons and of sputtered atoms, respectively. The yields of deposition, sputtering, and secondary electron emission, as well as the energy spectra of the secondary electrons were measured in situ during IBID using (CH3)3Pt(CPCH3) as functions of Ga+ ion incident angle (0°–45°) and energy (5–30 keV). The deposition yield and the secondary electron yield have the same angular dependences but very different energy dependences. It was also found that the deposition yield per secondary electron is very high (?10). However, within the investigated angle and energy ranges, the deposition yield is linearly related to the sputtering yield, the offset of which might be due to the contribution of primary ions. They conclude that the sputtered atom model describes IBID better than the secondary electron model.QN/Quantum NanoscienceApplied Science

Defect Control and <i>n</i>‑Doping of Encapsulated Graphene by Helium-Ion-Beam Irradiation

We study with Raman spectroscopy the influences of He⁺ bombardment and the environment on beam-induced defects in graphene encapsulated in hexagonal boron nitride (h-BN). We show for the first time experimentally the autonomous behavior of the D′ defect Raman peak: in contrast to the D defect peak, the D′ defect peak is sensitive to the local environment. In particular, it saturates with ion dose in the encapsulated graphene. Electrical measurements reveal <i>n</i>-type conduction in the BN-encapsulated graphene. We conclude that unbound atoms (“interfacials”) between the sp²-layers of graphene and h-BN promote self-healing of the beam-induced lattice damage and that nitrogen–carbon exchange leads to <i>n</i>-doping of graphene

A subwavelength slit as a quarter-wave retarder

We have experimentally studied the polarization-dependent transmission properties of a nanoslit in a gold film as a function of its width. The slit exhibits strong birefringence and dichroism. We find, surprisingly, that the transmission of the polarization parallel to the slit only disappears when the slit is much narrower than half a wavelength, while the transmission of the perpendicular component is reduced by the excitation of surface plasmons. We exploit the slit’s dichroism and birefringence to realize a quarter-wave retarder.QN/Quantum NanoscienceApplied Science