Dynamics and trajectory of nonautonomous rogue wave in a graded-index planar waveguide with oscillating refractive index

Bistability of a planar guiding structure with a nonlinear refractive index of the upper substrate and a lower linear substrate with a nonabrupt boundary is studied. The central guiding medium is assumed to be linear.

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Broadband Unidirectional Forward Scattering with High Refractive Index Nanostructures: Application in Solar Cells

Molecules ◽

10.3390/molecules26154421 ◽

2021 ◽

Vol 26 (15) ◽

pp. 4421

Author(s):

Ángela Barreda ◽

Pablo Albella ◽

Fernando Moreno ◽

Francisco González

Keyword(s):

Refractive Index ◽

Solar Cells ◽

Forward Direction ◽

High Refractive Index ◽

Incident Radiation ◽

Antireflection Coating ◽

Electromagnetic Response ◽

Silicon Substrates ◽

Graded Index ◽

Dielectric Substrates

High refractive index dielectric (HRID) nanoparticles are a clear alternative to metals in nanophotonic applications due to their low losses and directional scattering properties. It has been demonstrated that HRID dimers are more efficient scattering units than single nanoparticles in redirecting the incident radiation towards the forward direction. This effect was recently reported and is known as the “near zero-backward” scattering condition, attained when nanoparticles forming dimers strongly interact with each other. Here, we analyzed the electromagnetic response of HRID isolated nanoparticles and aggregates when deposited on monolayer and graded-index multilayer dielectric substrates. In particular, we studied the fraction of radiation that is scattered towards a substrate with known optical properties when the nanoparticles are located on its surface. We demonstrated that HRID dimers can increase the radiation emitted towards the substrate compared to that of isolated nanoparticles. However, this effect was only present for low values of the substrate refractive index. With the aim of observing the same effect for silicon substrates, we show that it is necessary to use a multilayer antireflection coating. We conclude that dimers of HRID nanoparticles on a graded-index multilayer substrate can increase the radiation scattered into a silicon photovoltaic wafer. The results in this work can be applied to the design of novel solar cells.

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Development of a Temperature-Controlled Optical Planar Waveguide Sensor with Lossy Mode Resonance for Refractive Index Measurement

Photonics ◽

10.3390/photonics8060199 ◽

2021 ◽

Vol 8 (6) ◽

pp. 199

Author(s):

Yu-Cheng Lin ◽

Liang-Yü Chen

Keyword(s):

Refractive Index ◽

Optical Fiber ◽

Temperature Control ◽

Planar Waveguide ◽

Metallic Oxide ◽

Refractive Index Measurement ◽

Index Measurement ◽

Temperature Controlled ◽

Optical Planar Waveguide ◽

Active Temperature

The generation of lossy mode resonances (LMR) with a metallic oxide film deposited on an optical fiber has attracted the attention of many applications. However, an LMR-based optical fiber sensor is frangible, and therefore it does not allow control of the temperature and is not suited to mass production. This paper aims to develop a temperature-controlled lossy mode resonance (TC-LMR) sensor on an optical planar waveguide with an active temperature control function in which an ITO film is not only used as the LMR resonance but also to provide the heating function to achieve the benefits of compact size and active temperature control. A simple flat model about the heat transfer mechanism is proposed to determine the heating time constant for the applied voltages. The TC-LMR sensor is evaluated experimentally for refractive index measurement using a glycerol solution. The heating temperature functions relative to the controlled voltages for water and glycerol are obtained to verify the performance of the TC-LMR sensor. The TC-LMR sensor is a valuable sensing device that can be used in clinical testing and point of care for programming heating with precise temperature control.

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A Simple Method for Prediction of Effective Core Area and Index of Refraction of Single-mode Graded Index Fiber in the Low V Region

Journal of Optical Communications ◽

10.1515/joc-2014-0020 ◽

2014 ◽

Vol 35 (4) ◽

Author(s):

Angshuman Majumdar ◽

Satabdi Das ◽

Sankar Gangopadhyay

Keyword(s):

Refractive Index ◽

Single Mode ◽

Index Of Refraction ◽

Core Area ◽

Exact Results ◽

Simple Method ◽

Graded Index ◽

Core Areas ◽

V Region ◽

User Friendly

AbstractBased on the simple power series formulation of fundamental mode developed by Chebyshev formalism in the low V region, we prescribe analytical expression for effective core area of graded index fiber. Taking step and parabolic index fibers as examples, we estimate the effective core areas as well as effective refractive index for different normalized frequencies (V number) having low values. We also show that our estimations match excellently with the available exact results. The concerned predictions by our method require little computation. Thus, this simple but accurate formalism will be user friendly for the system engineers.

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REFRACTIVE INDEX PROFILE RECONSTRUCTION OF PLANAR WAVEGUIDE FROM ITS MODE INTENSITY USING CHARACTERISTIC MATRIX METHOD

Journal of Nonlinear Optical Physics & Materials ◽

10.1142/s0218863501000528 ◽

2001 ◽

Vol 10 (02) ◽

pp. 169-179

Author(s):

HENRI P. URANUS ◽

M. O. TJIA

Keyword(s):

Refractive Index ◽

Intensity Distribution ◽

Planar Waveguide ◽

Nonlinear Least Squares ◽

Refractive Index Profile ◽

Characteristic Matrix ◽

Least Squares Regression ◽

Index Profile ◽

Measured Intensity ◽

Parameter Values

A method is proposed for the reconstruction of refractive index profile of planar waveguide from its fundamental mode intensity profile. The reconstruction is performed by fitting the calculated intensity distribution iteratively with the measured intensity distribution employing nonlinear least-squares regression technique. At each stage of iteration, new trial parameter values are generated and used to form a waveguide model approximated by a multilayer structure with stepwise index distribution, upon which the intensity distribution is then calculated by using the characteristic matrix technique. This method was numerically examined by using samples of either known or unknown analytic expression of the index profile.

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