Light propagation in a magneto-optical hyperbolic biaxial crystal

2017 ◽  
Vol 405 ◽  
pp. 164-170 ◽  
Author(s):  
Evgeniy V. Kuznetsov ◽  
Alexander M. Merzlikin
Keyword(s):  
Light Propagation ◽  
Biaxial Crystal

The Photoelastic Properties of Rubber. I. Theory of the Optical Properties of Strained Rubber

1948 ◽  
Vol 21 (2) ◽  
pp. 347-355
Author(s):  
L. R. G. Treloar
Keyword(s):  
Optical Constants ◽  
Light Propagation ◽  
Refractive Indices ◽  
Cube Root ◽  
Biaxial Crystal ◽  
Principal Stresses ◽  
Vulcanized Rubber ◽  
Principal Axes ◽  
The Difference ◽  
Homogeneous Strain

Abstract From the consideration of vulcanized rubber as a network of randomly kinked molecular chains, the optical constants corresponding to the most general type of homogeneous strain are derived. Under such a strain the rubber is shown to acquire the properties of an optically biaxial crystal, characterized by three principal refractive indices in the directions of the principal axes of strain. For directions of light propagation parallel to one of the principal axes, the birefringence is shown to be a simple function of the principal extensions and is, moreover, proportional to the difference between the two corresponding principal stresses. If the rubber is swollen with a liquid having the same refractive index as itself, the birefringence for a given state of strain varies inversely as the cube root of the swelling ratio, as do also the principal stresses.

Rubber Birefringence and Photoelasticity

1965 ◽  
Vol 38 (5) ◽  
pp. 1115-1163 ◽  
Author(s):  
A. Angioletti ◽  
S. Eccher ◽  
O. Polvara ◽  
V. Zerbini
Keyword(s):  
Light Propagation ◽  
Capillary Tube ◽  
Polarized Light ◽  
Extraordinary Wave ◽  
Biaxial Crystal ◽  
Ordinary Wave ◽  
Structural Anisotropy ◽  
Double Refraction ◽  
Single Wave ◽  
The Difference

Abstract The phenomenon of birefringence, discovered in 1669 by Erasmus Bartholin and later studied by Christian Huygens, is well known for its appearance in transparent crystalline solids. It is to be traced essentially to internal anisotropy of crystals for light propagation, so that under certain conditions a single wave front may give rise to multiple coherent waves which can cause double refraction or other phenomena such as the appearance of fringes varying in brightness and color due to interference of emerging wave fronts. Birefringence may be expressed as the difference of the velocities of propagation in various directions in the birefringent medium and particularly as the difference between the maximum and the minimum velocity or, alternatively, between the maximum and the minimum refractive index or even as the phase difference between emerging waves, given frequently as a number of wavelengths. While true double refraction phenomena may be observed with ordinary light when the difference n1−n2 between the refractive indexes is very high, the interference phenomena may be obtained only with polarized light, but may be observed even with very small differences between indexes. This is not the place to treat extensively general concepts like polarizer, analyzer, ordinary wave, extraordinary wave, uniaxial crystal, biaxial crystal, etc. which can be found in any good optics treatise. Birefringence is not in any way limited to crystalline media, possessing inherent structural anisotropy. It may also appear in bodies which are normally isotropic, when structural anisotropy is caused by external forces. Then birefringence is quantitatively dependent on force intensities, even if not always in an easily detectable way. This is called “accidental birefringence” or “stress-birefringence”. It was observed by Seebeck in 1813, and later studied in 1816 by Brewster for glass. It is observable in many transparent materials. Stress-birefringence is particularly conspicuous in macromolecular substances, including elastomers, vulcanized or not, where it is determined by the orientation of molecular links. This, of course, may not be ascribed altogether to stress, but sometimes also to partial crystallinity. Other phenomena of accidental birefringence may be observed in liquids or in solutions, especially of elastomers, when they are subjected to a velocity gradient, as when flowing through a capillary tube or, more commonly, when sheared between two coaxial cylinders.

Holographic moving picture recording and observation of ultrashort pulsed laser light propagation

2008 ◽  
Vol 36 (Supplement) ◽  
pp. 201-202
Author(s):  
Yasuhiro Awatsuji ◽  
Kenzo Nishio ◽  
Shogo Ura ◽  
Toshihiro Kubota
Keyword(s):  
Light Propagation ◽  
Laser Light ◽  
Pulsed Laser ◽  
Ultrashort Pulsed Laser

scholarly journals OAM light propagation through tissue

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Netanel Biton ◽  
Judy Kupferman ◽  
Shlomi Arnon
Keyword(s):  
Light Propagation ◽  
Biological Imaging ◽  
Gaussian Beams ◽  
Medical Implants ◽  
Optical Wireless ◽  
Scattering Media ◽  
Valuable Contribution ◽  
Light Beams ◽  
First Time ◽  
Diffuse Media

AbstractA major challenge in use of the optical spectrum for communication and imaging applications is the scattering of light as it passes through diffuse media. Recent studies indicate that light beams with orbital angular momentum (OAM) can penetrate deeper through diffuse media than simple Gaussian beams. To the best knowledge of the authors, in this paper we describe for the first time an experiment examining transmission of OAM beams through biological tissue with thickness of up to a few centimeters, and for OAM modes reaching up to 20. Our results indicate that OAM beams do indeed show a higher transmittance relative to Gaussian beams, and that the greater the OAM, the higher the transmittance also up to 20, Our results extend measured results to highly multi scattering media and indicate that at 2.6 cm tissue thickness for OAM of order 20, we measure nearly 30% more power in comparison to a Gaussian beam. In addition, we develop a mathematical model describing the improved permeability. This work shows that OAM beams can be a valuable contribution to optical wireless communication (OWC) for medical implants, optical biological imaging, as well as recent innovative applications of medical diagnosis.

scholarly journals Recent advancements and perspectives on light management and high performance in perovskite light-emitting diodes

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shaoni Kar ◽  
Nur Fadilah Jamaludin ◽  
Natalia Yantara ◽  
Subodh G. Mhaisalkar ◽  
Wei Lin Leong
Keyword(s):  
High Performance ◽  
Light Propagation ◽  
Light Emission ◽  
Review Article ◽  
Rapid Progress ◽  
Light Emitting ◽  
Materials Engineering ◽  
Perovskite Materials ◽  
Light Management ◽  
Photon Recycling

Abstract Perovskite semiconductors have experienced meteoric rise in a variety of optoelectronic applications. With a strong foothold on photovoltaics, much focus now lies on their light emission applications. Rapid progress in materials engineering have led to the demonstration of external quantum efficiencies that surpass the previously established theoretical limits. However, there remains much scope to further optimize the light propagation inside the device stack through careful tailoring of the optical processes that take place at the bulk and interface levels. Photon recycling in the emitter material followed by efficient outcoupling can result in boosting external efficiencies up to 100%. In addition, the poor ambient and operational stability of these materials and devices restrict further commercialization efforts. With best operational lifetimes of only a few hours reported, there is a long way to go before perovskite LEDs can be perceived as reliable alternatives to more established technologies like organic or quantum dot-based LED devices. This review article starts with the discussions of the mechanism of luminescence in these perovskite materials and factors impacting it. It then looks at the possible routes to achieve efficient outcoupling through nanostructuring of the emitter and the substrate. Next, we analyse the instability issues of perovskite-based LEDs from a photophysical standpoint, taking into consideration the underlying phenomena pertaining to defects, and summarize recent advances in mitigating the same. Finally, we provide an outlook on the possible routes forward for the field and propose new avenues to maximally exploit the excellent light-emitting capabilities of this family of semiconductors.

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