Characterization of anisotropy of the porous anodic alumina by the Mueller matrix imaging method

Abstract

Porous anodic alumina (PAA) is a photonic crystal with a hexagonal porous structure. To learn more about the effects brought by pores on the anisotropy of the PAA, we use the orientation sensitive Mueller matrix imaging (MMI) method to study it. We fabricated the PAA samples with uniform pores and two different pore diameters. By the MMI experiments with these samples, we found that the birefringence is the major anisotropy of the PAA and that there are many small areas with different orientations that formed spontaneously in the process of production on the surface of the PAA. By the MMI experiments at different orientations of the sample with two different pore diameters, we found that the pores affect the birefringence of the sample and the effect increases with the increased inclination of the sample. To further analyze the PAA, we present a symmetrical rotation measurement method according to the Mueller matrix of the retarder. With this method, we can calculate the average refractive index (RI) of birefringence and the orientation of the optical axis of uniaxial crystal. The results also show the effect of the pores on the anisotropy of PAA.

Morphological Control: Properties and Applications of Metal Nanostructures

“…Using soft molds such as rod-shaped micelles, Ag and gold nanowires and nanowires with controllable diameters and dimensional ratios can be synthesized. Bar-shaped micelles are obtained by selfassembly of cetyltrimethylammonium bromide (CTAB) or liquid crystalline phases consisting of sodium bis (2-ethylhexyl) sulfosuccinate, para-xylene, and water [21][22][23][24][25]. Also, the two-layer acetyl amine/water system is used as a soft mold for the production of Ag nanosheets.…”

“…Gold nano rods, gold nano cages, and hollow nanospheres have near-infrared absorption [19][20][21]. Surface-enhanced Raman scattering (SERS) is more suitable for silver nanostructures with sharp corners and edges than spherical (edgeless) silver nanoparticles [22][23][24][25]. Usually, 1-10 nm metal nanoparticles have good electron and optical effects due to their free electron path [26][27][28].…”

Angular-Based Mueller Matrix Polarimetry Parameters for Subwavelength Pore Size Differentiation

“…The fabricated sample is imaged under a scanning electron microscope, and Figure 2 shows the top and side view of the PAA sample. For the detailed fabrication process, please refer to [1].…”

“…In this work, the idea of angular parameter-based microstructure feature parameters is explored and experimented. Using the porous anodic alumina (PAA) Mueller matrix polarimetry measurement data from the published work of Chuhui Wang [1], it is discovered that while the rotation-invariant parameters could not differentiate the pore size, the proposed parameter can not only differentiate areas with different pore sizes but also do so with a simple explicit analytical form. Through this study, we emphasized the importance of angular parameters in Mueller matrix polarimetry, demonstrated their potential for differentiating different microstructures, and hopefully inspired future research in this area.…”

Optical Properties of Porous Alumina Assisted Niobia Nanostructured Films–Designing 2-D Photonic Crystals Based on Hexagonally Arranged Nanocolumns

“…This spontaneously emerging structure is controllable in various ways within wide limits [ 33 , 60 , 61 ], which allows the synthesis of composite and functional materials [ 43 ] for electronic devices [ 62 , 63 ], various kinds of sensors [ 54 , 64 , 65 , 66 , 67 , 68 ], and other optically active materials [ 29 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 ], including metamaterials [ 78 ] and materials for solar cells and solar fuel production [ 53 , 54 , 79 ] and other energy storage applications [ 55 , 80 , 81 ]. It should be noted that the porous structure of native X-ray amorphous porous-alumina (PA) makes it an anisotropic material [ 82 ], imparting properties characteristic of anisotropic crystals, including, for example, birefringence [ 83 , 84 ]. Among the objects of nano-optics, photonic crystals (PCs) that have a spatially periodic refractive index, with intervals on the order of the wavelength of light, possessing a photonic band gap [ 85 , 86 ], are of interest.…”