scholarly journals Formation of half-period surface relief gratings in azobenzene containing polymer films

2020 ◽  
Vol 126 (9) ◽  
Author(s):  
Joachim Jelken ◽  
Carsten Henkel ◽  
Svetlana Santer
Keyword(s):  
Polymer Film ◽  
Polymer Films ◽  
Surface Relief ◽  
Incident Light ◽  
Glassy State ◽  
Polarized Light ◽  
Half Period ◽  
Polarization Distribution ◽  
Linearly Polarized ◽  
Set Up

Abstract We study the peculiar response of photo-sensitive polymer films irradiated with a certain type of interference pattern where one interfering beam is S-polarized, while the second one is P-polarized. The polymer film, although in a glassy state, deforms following the local polarization distribution of the incident light, and a surface relief grating (SRG) appears whose period is half the optical one. All other types of interference patterns result in the matching of both periods. The topographical response is triggered by the alignment of photo-responsive azobenzene containing polymer side chains orthogonal to the local electrical field, resulting in a bulk birefringence grating (BBG). We investigate the process of dual grating formation (SRG and BBG) in a polymer film utilizing a dedicated set-up that combines probe beam diffraction and atomic force microscopy (AFM) measurements, and permits acquiring in situ and in real-time information about changes in local topography and birefringence. We find that the SRG maxima appear at the positions of linearly polarized light (tilted by 45° relative to the grating vector), causing the formation of the half-period topography. This permits to inscribe symmetric and asymmetric topography gratings with sub-wavelength period, while changing only slightly the polarization of one of the interfering beams. We demonstrate an easy generation of sawtooth profiles (blazed gratings) with adjustable shape. With these results, we have taken a significant step in understanding the photo-induced deformation of azo-polymer films.

Oriented Polymer/Metal Nanocomposites: A New Method for the Production of Polarization Dependent Color Filters

1999 ◽  
Vol 559 ◽  
Author(s):  
Yvo Dirix ◽  
Cees Bastiaansen ◽  
Walter Caseri ◽  
Paul Smith
Keyword(s):  
Absorption Spectrum ◽  
Ostwald Ripening ◽  
Incident Light ◽  
Polarized Light ◽  
Nanocomposite Films ◽  
Color Filter ◽  
Vibration Direction ◽  
Aspect Ratios ◽  
Linearly Polarized ◽  
Set Up

ABSTRACTUniaxially oriented composites of high-density polyethylene and silver nanoparticles were prepared using solution-casting, melt-extrusion and solid-state drawing techniques. The absorption spectrum in the visible wavelength range of the drawn nanocomposites was observed to strongly depend on the polarization direction of the incident light. For instance, the nanocomposites appear bright yellow or red when the vibration direction of linearly polarized light is perpendicular or parallel, respectively, to the drawing axis. The optical anisotropy of the drawn nanocomposites originates from uniaxially oriented, pearl-necklace type of arrays of nanoparticles of high aspect ratios. The absorption spectrum of the nanocomposites can be shifted to higher wavelengths using appropriate annealing procedures. The annealing results in an increased size of the primary silver particles, due to Ostwald ripening, and consequently a range of polarization-dependent colors can be generated in the drawn nanocomposites. It is suggested that the drawn nanocomposite films can be used in liquid crystal displays (LCD's) were they serve a dual purpose in combining polarization filter and color filter. The new display configuration transmits colored light in both the on- and off-state of the device, this in contrast to a conventional color LCD which only transmits colored light in the off-state. As a consequence, an enhanced brightness and light (energy) efficiency of the new display set-up is envisioned.

Visual pigments and dichroism of anchovy cones: A model system for polarization detection.

2002 ◽  
Vol 19 (4) ◽  
pp. 467-473 ◽  
Author(s):  
IÑIGO NOVALES FLAMARIQUE ◽  
FERENC I. HÁROSI
Keyword(s):  
Detection System ◽  
Incident Light ◽  
Polarized Light ◽  
Visual Pigments ◽  
Rods And Cones ◽  
Lamellar Orientation ◽  
Cone System ◽  
Linearly Polarized ◽  
Bay Anchovy ◽  
Polarization Detection

The retinas of anchovies have two unique photoreceptor types: “bifid” and “long” cones (Fineran & Nicol, 1976). The outer segments of these cells contain multiple layers of membranes (lamellae) oriented longitudinally (axially). This orientation is distinct from that in all other vertebrate rods and cones, where the lamellae are stacked transversely with their planes perpendicular to the incident light path. Although the common arrangement provides optimal absorption for normally incident light rays, it is also insensitive to the rays' direction of vibration (i.e. their polarization). In contrast, the two mutually perpendicular sets of axially oriented lamellae segregated into bifid and long cones could function as the principal analyzers for linearly polarized light, as previously hypothesized (Fineran & Nicol, 1976, 1978). Here, we report on a microspectrophotometric study that shows (1) the presence of two spectrally distinct visual pigments in the three photoreceptor types of the bay anchovy retina; these are typical vertebrate pigments in that they bleach, when exposed to light, and have absorption spectra like all other vitamin A1-based visual pigments; (2) that the rods and cones exhibit dichroic absorption of light in accordance with their lamellar orientation, and (3) that the two cone types of the retina contain a spectrally indistinguishable pigment with peak absorbance (λmax) around 540 nm, while the rods contain a rhodopsin-like pigment with λmax near 500 nm. Compared to other vertebrates, anchovies are remarkable for using a monochromatic cone system with unusual specializations supportive of a polarization detection system.

Study on Polarization Distribution of Polarization Encoder in Oblique Incidence

2011 ◽  
Vol 201-203 ◽  
pp. 1590-1595
Author(s):  
Mu Zhun Zhou ◽  
Yan Ru Chen ◽  
Qi Zhao ◽  
Yu Xin
Keyword(s):  
Theoretical Calculations ◽  
Incident Light ◽  
Polarization State ◽  
Polarized Light ◽  
Linbo3 Crystal ◽  
Polarization Distribution ◽  
Electro Optic ◽  
Measurement Results ◽  
Polarization Encoding ◽  
Elliptically Polarized

Principle of polarization encoding based on electro-optic effect of LiNbO3 crystal is analyzed, effact on polarization encoding optical field effects is studied when the incident light direction changes. Theoretical calculations show that, with the angle between the direction of incident laser beam and the main axis of LiNbO3 crystal increases, rotation angle of polarization ellipse remain unchanged,but ellipticity changes at any other position except in the center of the encoder,at the top and bottom of encoder,polarization state changes from circularly polarized to elliptically polarized,at other position of the encoder, polarization states are still elliptically polarized light but with different ellipticity angle. Experiment measurement results are in accord with ones of the calculation.

scholarly journals Multifunctional Metasurface Lens With Tunable Focus Based on Phase Transition Material

2021 ◽  
Vol 9 ◽  
Author(s):  
Yongkang Song ◽  
Weici Liu ◽  
Xiaolei Wang ◽  
Faqiang Wang ◽  
Zhongchao Wei ◽  
...  
Keyword(s):  
Phase Transition ◽  
Light Field ◽  
Focal Point ◽  
Incident Light ◽  
Polarization State ◽  
Polarized Light ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Multiple Focus ◽  
Linearly Polarized

Metasurfaces have powerful light field manipulation capabilities, which have been extensively studied in the past few years and have developed rapidly in various fields. At present, the focus of metasurface research has shifted to the tunable functionality. In this paper, a temperature-controllable multifunctional metasurface lens based on phase transition material is designed. First of all, by controlling the temperature of the desired working area and the polarization of the incident light, switching among multiple focus, single focus, and no focus at any position can be achieved, and the intensity and helicity of the output light can be adjusted. In addition, a polarization-sensitive intensity-tunable metalens based on the P-B phase principle is designed, when the incident light is linearly polarized light, left-handed circularly polarized light, or right-handed circularly polarized light, it has the same focal point but with different light field intensities. Therefore, the focused intensity can be tunable by the polarization state of the incident light.

Angular Offset Splicing of Polarization Maintained (PANDA) Optical Fibers in an Electronics Manufacturing Environment

2009 ◽  
Author(s):  
Rohan Kulkarni ◽  
Krishnaswami Srihari
Keyword(s):  
Optical Fibers ◽  
Research Effort ◽  
Angular Displacement ◽  
Incident Light ◽  
Polarized Light ◽  
Phase Changes ◽  
Electronic Manufacturing ◽  
Splice Loss ◽  
Offset Distance ◽  
Set Up

Panda fibers are used in applications where polarized light is required as an input. Panda fibers do not polarize the light passed through them but maintain the polarization of the incident light. The focus of this research endeavor is restricted to the angular offset splicing process of Polarization Maintaining (PM) panda fibers during optoelectronic assembly. In the splicing process, two or more fiber ends are fused together using a high electric discharge in such a manner that a minimum amount of losses are introduced [1]. However, in this particular research effort, angular offset was used to perform the splicing of panda fibers. Angular displacement is not desired during the splicing of panda fibers as it introduces losses due to phase changes that are caused because of the misalignment of stress rods. This study observes the effects of angular displacement on the splice loss. This paper focuses on the angular offset splicing of Panda fibers. The objective of the study was to observe the effect of angular displacement on the splice loss during the angular offset splicing process for panda fibers and outline the splicing parameters that have a significant impact on the splice loss. A design of experiments (DOE) approach has been used to perform the splicing. Even though the splicer provides a loss estimate, a real time splice loss measurement set up using a power meter and source was used to measure the actual loss. Offset distance, target loss and angular displacement were the factors selected for experimentation. Experiments were conducted using the aforementioned parameters. An effort has been made to obtain ‘best’ combination values for the significant parameters that can be used for production in an Electronic Manufacturing Services (EMS) provider’s environment.

scholarly journals Metasurface of Combined Semicircular Rings with Orthogonal Slit Pairs for Generation of Dual Vector Beams

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1718
Author(s):  
Qian Kong ◽  
Manna Gu ◽  
Xiangyu Zeng ◽  
Rui Sun ◽  
Yuqin Zhang ◽  
...  
Keyword(s):  
Time Domain ◽  
Finite Difference Time Domain ◽  
Polarized Light ◽  
Orientation Angle ◽  
Fdtd Simulation ◽  
Dual Vector ◽  
Vector Beams ◽  
Linearly Polarized ◽  
Potential Applications ◽  
Difference Time

Manipulation of multichannel vector beams (VBs) with metasurfaces is an important topic and holds potential applications in information technology. In this paper, we propose a novel metasurface for the generation of dual VBs, which is composed of orthogonal slit pairs arranged on multiple groups of combined semicircular rings (CSRs). A group of CSRs include a right-shifted set and a left-shifted set of semicircular rings, and each set of semicircular rings has two halves of circles with different radii, sharing the same shifted center. Under the illumination of linearly polarized light, the two shifted sets of semicircular rings generate the two VBs at the shifted center positions on the observation plane. The slit units of each set are designed with independent rotation order and initial orientation angle. By adjusting the linear polarization of illumination, both two VBs with their orders and polarization states are independently controlled simultaneously. The principle and design are demonstrated by the finite-difference time domain (FDTD) simulation. The work is of significance for miniatured devices of VB generators and for related applications.

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