Orientation dependence in high harmonics of ZnO with polarization corrections to counteract the birefringent effect

We investigate the influence of the birefringence on the high-order harmonics in an a-cut Zn O crystal with midinfrared laser pulses.The high harmonics exhibit strong dependence on the alignment of the crystal with respect to the laser polarization.We introduce the Jones calculus to counteract the birefringent effect and obtain the harmonics with polarization corrections in Zn O.We show that the birefringent effect plays an important role in the orientation dependence of HHG.

Geometric and physical configurations of meta-atoms for advanced metasurface holography

Metasurfaces consisting of subwavelength structures,so-called meta-atoms,have steadily attracted considerable attention for advanced holography due to their advantages in terms of high-resolution holographic images,large field of view,and compact device volume.In contrast to conventional holographic displays using bulky conventional diffractive optical elements,metasurface holography enables arbitrary complex wavefront shaping with a much smaller footprint.In this review,we classify metasurface holography according to the meta-atom design methodologies,which can further expand hologram functionalities.We describe light-matter interactions,particularly in metasurface systems,using the relevant the Jones matrix to rigorously explain modulations of the amplitude,phase,and polarization of light.Six different types of metaatoms are presented,and the corresponding achievable wavefronts that form the holographic images in the far-field are also provided.Such a simple classification will give a straightforward approach to design and further realize advanced metasurface holographic devices.

Quantifying the refractive index dispersion of a pigmented biological tissue using Jamin–Lebedeff interference microscopy

Jamin–Lebedeff polarizing interference microscopy is a classical method for determining the refractive index and thickness of transparent tissues.Here,we extend the application of this method to pigmented,absorbing biological tissues,based on a theoretical derivation using Jones calculus.This novel method is applied to the wings of the American Rubyspot damselfly,Hetaerina americana.The membranes in the red-colored parts of the damselfly’s wings,with a thickness of 2.5 μm,contain a pigment with maximal absorption at 490 nm and a peak absorbance coefficient of 0.7 μm^(-1).The high pigment density causes a considerable and anomalous dispersion of the refractive index.This result can be quantitatively understood from the pigment absorbance spectrum by applying the Kramers–Kronig dispersion relations.Measurements of the spectral dependence of the refractive index and the absorption are valuable for gaining quantitative insight into how the material properties of animal tissues influence coloration.