scholarly journals Dual gratings interspersed on a single butterfly scale

2008 ◽  
Vol 5 (28) ◽  
pp. 1387-1390 ◽  
Author(s):  
Abigail L Ingram ◽  
Virginie Lousse ◽  
Andrew R Parker ◽  
Jean Pol Vigneron
Keyword(s):  
Spectral Range ◽  
Incident Light ◽  
Diffraction Order ◽  
Butterfly Wing ◽  
Photonic Structure ◽  
Photonic Structures ◽  
Optical Signature ◽  
Threat Displays ◽  
Single Structure ◽  
Male Wing

Iridescent butterfly wing colours result from the interaction of light with sub-micrometre structures in the scales. Typically, one scale contains one such photonic structure that produces a single iridescent signal. Here, however, we show how the dorsal wings of male Lamprolenis nitida emit two independent signals from two separate photonic structures in the same scale. Multiple independent signals from separate photonic structures within the same sub-micrometre device are currently unknown in animals. However, they would serve to increase the complexity and specificity of the optical signature, enhancing the information conveyed. This could be important during intrasexual encounters, in which iridescent male wing colours are employed as threat displays. Blazed diffraction gratings, like those found in L. nitida , are asymmetric photonic structures and drive most of the incident light into one diffraction order. Similar gratings are used in spectrometers, limiting the spectral range over which the spectrometer functions. By incorporating two interchangeable gratings onto a single structure, as they are in L. nitida , the functional range of spectrometers could be extended.

scholarly journals Orientation-Dependent Reflection of Structurally Coloured Butterflies

Biomimetics ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 5
Author(s):  
Sigrid Zobl ◽  
Bodo D. Wilts ◽  
Willi Salvenmoser ◽  
Peter Pölt ◽  
Ille C. Gebeshuber ◽  
...  
Keyword(s):  
Orientation Dependence ◽  
Butterfly Species ◽  
Butterfly Wing ◽  
Step Size ◽  
Photonic Structures ◽  
Light Interference ◽  
Important Input ◽  
Individual Scale ◽  
The Individual ◽  
Wing Scales

The photonic structures of butterfly wing scales are widely known to cause angle-dependent colours by light interference with nanostructures present in the wing scales. Here, we quantify the relevance of the horizontal alignment of the butterfly wing scales on the wing. The orientation-dependent reflection was measured at four different azimuth angles, with a step size of 90°, for ten samples—two of different areas of the same species—of eight butterfly species of three subfamilies at constant angles of illumination and observation. For the observed species with varying optical structures, the wing typically exhibits higher orientation-dependent reflections than the individual scale. We find that the measured anisotropy is caused by the commonly observed grating structures that can be found on all butterfly wing scales, rather than the local photonic structures. Our results show that the technique employed here can be used to quickly evaluate the orientation-dependence of the reflection and hence provide important input for bio-inspired applications, e.g., to identify whether the respective structure is suitable as a template for nano-imprinting techniques.

Light guidance in photonic structures of Morpho butterfly wing scales

2020 ◽  
Vol 126 (10) ◽  
Author(s):  
Magali Thomé ◽  
Elodie Richalot ◽  
Serge Berthier
Keyword(s):  
Butterfly Wing ◽  
Photonic Structures ◽  
Morpho Butterfly ◽  
Light Guidance ◽  
Wing Scales

Photonic structure arrays generated using butterfly wing scales as biological units

2015 ◽  
Vol 3 (9) ◽  
pp. 1743-1747 ◽  
Author(s):  
Xinchun Tian ◽  
Guofen Song ◽  
Xiang Ding ◽  
Jiajun Gu ◽  
Qinglei Liu ◽  
...  
Keyword(s):  
Molecular Interactions ◽  
Chemical Bonds ◽  
Butterfly Wing ◽  
Photonic Structure ◽  
Wing Scales

Photonic structure arrays composed of biological units have been generated via a binding difference between molecular interactions and chemical bonds.

INVESTIGATION OF THERMAL RADIATION ANGULAR AND POLARIZATION CHARACTERISTICS OF ONE-DIMENSIONAL PHOTONIC STRUCTURES ON A FINITE SUBSTRATE

2021 ◽  
Vol 56 ◽  
pp. 83-88
Author(s):  
V. P. Maslov ◽  
Keyword(s):  
Thermal Radiation ◽  
Experimental Studies ◽  
Radiation Energy ◽  
Infrared Range ◽  
Photonic Structure ◽  
Ir Radiation ◽  
Directional Diagram ◽  
One Dimensional ◽  
Photonic Structures ◽  
Polarization Characteristics

One-dimensional photonic structures (PS) are the layered metamaterials, which optical properties are due to interference effects within the structure. Due to the interaction of electromagnetic waves with the periodic structure, the thermal radiation (TR) of such PS has the features of coherent: it has a selective spectrum and a petal pattern. The relevance of TR PS research is due to the search for new materials to create sources of infrared (IR) radiation in the middle and far IR range (with a wavelength > 5 μm). The second important area of application of the radiating properties of the PS is the creation of non-radiating coatings to remove unwanted TR from the heated surfaces of the IR devices. Despite the fact that the irradiative properties of PS have been studied quite well, in the literature insufficient attention is paid to the influence of the finite substrate on the parameters of TR structures. The influence of a finite incoherent substrate on the angular and polarization characteristics of the thermal radiation of the system (photonic structure)/substrate has been investigated. Systems consisting of plane-parallel Ge or Si plates as PS and incoherent BaF2, BaF2/Al and Al substrates were used in experimental studies. It has been established, the contrast and amplitude of the directional diagram petals of the TR system depend on the ratio of the optical characteristics of the photonic structure and the substrate. The presence of a strongly reflective substrate eliminates the difference between the angular dependences of the s- and p-polarized components of the TR. In the case when the PS is placed on a transparent incoherent substrate with a lower refractive index, there is an increase in the p-polarized component of the TR and the suppression of the s-polarized. The thermal imaging picture of the TR angular distribution of the Si/Al system has been recorded and it was experimentally proved that the TR of photonic systems exhibits circular patterns. The results of the work can be used in the development of narrowband emitters in the middle and far infrared range, coatings to increase radiation energy exchange and coatings with minimal emissivity that are invisible in the thermal range.

Experimental Design for Free Space Nonlinear Magnetic Material Characterization Using Photonic Structures

2008 ◽  
Vol 1118 ◽  
Author(s):  
Eric Kuster ◽  
Ricky L. Moore
Keyword(s):  
Magnetic Field ◽  
Experimental Design ◽  
Power Density ◽  
Free Space ◽  
Particulate Composites ◽  
Photonic Structure ◽  
Critical Fields ◽  
Pump Frequency ◽  
Photonic Structures ◽  
Field Localization

ABSTRACTMeasuring nonlinear AC dielectric or magnetic properties of ferro and ferri magnetic materials has often required large, extremely high power and bulky equipment configurations for production of the required intense electric and/or magnetic fields. Multiple RF cavities, striplines or waveguide test fixtures may be required. The techniques often require 10s of cubic millimeter too centimeter material volumes. This paper presents results from an initial experimental design of a free space based measurement configuration for small material volumes such as nano and micro particulates or particulate composites. The technique uses wideband radiators and modest variable power radio frequency pumping sources. A second design uses, in concert with a higher power pump, a variable frequency low power probe source at frequencies other than that of the pump. A two dimensional photonic bandgap (PBG) structure is common to both configurations. The photonic structure acts to enhance power density at frequencies associated with localized electromagnetic fields constrained to small volumes of the photonic structures. Field localization is recognized and has been applied in biological diagnostics and treatment [Phys. Rev. v109, 1492; Phys. Rev. B, v55 and 62, n. 19 and 16, pp 13234 and 11230 and Chem.Soc.News, 1998, v27, p241].Modeling of various measurement configurations is based upon expansion of incident and propagating fields in characteristic modes external and within the structure. A proper choice of photonic structure, material and pump frequency is found to localize fields in air, between the structural dielectric members of the photonic structure. This will allow small magnetic or electric samples to be inserted for exposure in these regions. The electromagnetic reflection, transmission, absorption and field/power density multiplier of the photonic structure can be measured at multiple frequencies and reflect the dielectric or magnetic nonlinearity and changed dispersion induced at the pump frequency. One PBG-free space combination will be presented that finds power density multipliers of 10 6. Thus a 10 watt pump source will produce RF magnetic field strengths near 10 Oe. This magnetic field should be sufficient to exceed critical fields for many ferri and ferromagnetic samples inserted in the volume of field localization.

Photonic structures with grating couplers based on ZnO

2011 ◽  
Vol 19 (4) ◽  
Author(s):  
P. Struk ◽  
T. Pustelny ◽  
K. Gołaszewska ◽  
E. Kamińska ◽  
M. Borysiewicz ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Planar Waveguide ◽  
Experimental Investigations ◽  
Geometrical Parameters ◽  
Photonic Structure ◽  
Grating Couplers ◽  
Numerical Investigations ◽  
Photonic Structures ◽  
Input And Output ◽  
Wideband Gap

AbstractThe paper presents investigations concerning the design and realization of photonic structures with grating couplers. The first part of the paper deals with basic theoretical information on photonic structures with grating couplers and their application in optoelectronics. The further part presents the results of numerical investigations on photonic structures with grating couplers and shows the influence of geometrical parameters on the effectiveness of the input and output of optic power into and out of this photonic structure. The paper also provides the results of experimental investigations on a wideband gap semiconductor, viz. zinc oxide ZnO, as well as its application in planar waveguide structures and photonic structures with grating couplers.

Selection of Voltage and Spectral Range in Liquid Crystal Gating

2010 ◽  
Vol 428-429 ◽  
pp. 406-410
Author(s):  
Han Cheng Liu ◽  
Hua Wa Yu ◽  
Xiang An Yan ◽  
Jun Fang Wu
Keyword(s):  
Liquid Crystal ◽  
Wavelength Range ◽  
Spectral Range ◽  
Incident Light ◽  
Extinction Ratio ◽  
Low Light ◽  
Incident Wavelength ◽  
Reflected Light ◽  
Point Control ◽  
Selection Of

Liquid crystal device (LCD) used as spatial gating apparatus has a lot of new using at low light detecting, imaging spectrum and so on. Since LCD's lattice characteristic, it can come true point gating, local field gating and whole surface gating. It can carry out point-by-point control and feedback of imaging cooperating with CCD detector. Some characteristics of we used LCD, LCX023CMT (SONY), have been detected in order to use conveniently, those include spectra transmittance and which’s changing with gating voltage. The results show that when incident wavelength more than 650nm, this LCD couldn't be used as spatial gating because of polaroid's extinction ratio becoming worse; LCD can modulate the incident light from 400 to 650nm, and the modulates of wavelength range, extent and linearity were related to the modulate voltage clearly. The results indicate that LCD modulates the incident light better and better at voltage more than 2.5V for 550nm; the action modulated become linear with voltage approximately; the modulate extent goes to saturation at voltage more than 5V, and the spectral range modulated is steady in 400-650nm. At voltage more than 5V, transmittance of spectrum is a horizontal beeline almost with incident wavelength range from 400 to 650nm. This indicates that transmittance of spectrum in this range is same, and liquid crystal has none selectivity in colored light. As a result, there is no chromatism between transmitted and incident light. However, because that there is lower transmittance, the reflected light can be used which can ensure not only effective using ratio of light, but also the consistency between reflected and incident light.

Nonpolar-Oriented GaN Films for Polarization-Sensitive and Narrow-Band Photodetectors

MRS Bulletin ◽  
2009 ◽  
Vol 34 (5) ◽  
pp. 341-347 ◽  
Author(s):  
Holger T. Grahn
Keyword(s):  
Spectral Range ◽  
Linear Polarization ◽  
Energy Gap ◽  
Narrow Band ◽  
Large Strain ◽  
Incident Light ◽  
Compressive Strain ◽  
Polarization State ◽  
Polarization Filter ◽  
Linearly Polarized

AbstractThis article reviews the optical polarization properties of unstrained and strained GaN films with a nonpolar orientation. In unstrained a -plane GaN films, the A exciton becomes completely linearly polarized perpendicular to the c-axis, whereas the B and C excitons are only partially polarized. In m -plane or a -plane GaN films under anisotropic in-plane compressive strain, all three interband transitions between the three uppermost valence bands and the conduction band can become linearly polarized for sufficiently large strain values. The complete linear polarization can be directly observed in reflection, transmission, or photoreflectance by a polarization-dependent energy gap. This complete linear polarization can be used to realize polarization-sensitive photodetectors in the ultraviolet spectral range, which do not need a polarization filter in front of the photodetector. By combining a polarization filter and photodetector or two photodetectors from the same material with their c-axes oriented perpendicular to each other, a narrowband photodetection configuration can be achieved in the ultraviolet spectral range with a band width below 8 nm. Since both realizations are also polarization sensitive, a configuration with four photodetectors is necessary to achieve narrow-band sensitivity regardless of the polarization state of the incident light. At the same time, the configuration with four photodetectors allows for the determination of the absolute angle of polarization.

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