The dependence of the dynamic range of the phase generated carrier (PGC) technique on low-pass filters passbands is investigated using a simulation model. A nonlinear character of this dependence, which could lead to dynamic range limitations or measurement uncertainty, is presented for the first time. A detailed theoretical analysis is provided to verify the simulation results and these results are consistent with performed calculations. The method for the calculation of low-pass filters passbands according to the required dynamic range upper limit is proposed.

M. J. Plotnikov

A. V. Kulikov

V. E. Strigalev

I. K. Meshkovsky

Dynamic Range Analysis of the Phase Generated Carrier Demodulation Technique

Accurate simulation from digital, submicron, optical elements is obtained by finite difference time domain (FDTD) results that are phase analyzed as sources for Huygens wavelets on fine scales much shorter than the wavelength used. Results, from the MIT electromagnetic evaluation program, are renormalized by a method here called &#x201c;refractive impulse.&#x201d; This is valid for polarized responses from digital diffractive and focusing optics. The method is employed with plane wave incidence at any angle or with diverging or converging beams. It is more systematic, more versatile, and more accurate than commercial substitutes.

Antony J. Bourdillon

Optical Response to Submicron Digital Elements Simulated by FDTD Wavelets with Refractive Impulse

Effective density of vibrational states in H-bonded liquids was measured by Raman scattering method. Actuality of a low-frequency part of the spectrum of the intermediate (fracton) region, which obeys a power law, indicates the correct application of the percolation model. The dependence of exponent on binary solutions concentration has been studied. Existence of correlation of the fractal structure parameter and dynamic viscosity has been noted.

Nataliia Kuzkova

Andrey Yakunov

Mykola Bilyi

Low-Frequency Raman Spectroscopic Monitoring of Supramolecular Structure in H-Bonded Liquids

This paper describes the state-of-the-art of polarization multiplexing for optical networks transmission. The use of polarization division multiplexing (PDM) permits to multiply the user capacity and increase the spectral efficiency. Combining PDM and orthogonal frequency division multiplexed (OFDM) modulation allows maximizing the optical transmission capacity. The experimental demonstration of transmitting OFDM signals following ECMA-368 ultrawide band (UWB) standard in radio-over-fiber using PDM in passive optical networks is herein reported. The impact of cross-polarization and cochannel crosstalk is evaluated experimentally in a three-user OFDM-UWB subcarrier multiplexed (SCM) configuration per polarization. Each SCM uses up to three OFDM-UWB channels of 200&#x2009;Mbit/s each, achieving an aggregated bitrate of 1.2&#x2009;Gbit/s with 0.76&#x2009;bit/s/Hz spectral efficiency when using PDM transmission. The experimental results for the polarization-multiplexed SCM indicate that a 4&#x2009;dB additional polarization crosstalk interference can be expected compared to a nonpolarization-multiplexed transmission system which translates to 2.4&#x2009;dB EVM penalty in the UWB signals. The successful PDM transmission of SCM multiuser OFDM-UWB over a passive optical network of 25&#x2009;km standard-single mode fiber (SSMF) reach is demonstrated.

Maria Morant

Joaquin P&#xe9;rez

Roberto Llorente

Polarization Division Multiplexing of OFDM Radio-over-Fiber Signals in Passive Optical Networks

Theoretically, the characteristics matrix method is employed to investigate and compare the properties of the band gaps of the one-dimensional ternary and binary lossy photonic crystals which are composed of double-negative and double-positive materials. This study shows that by varying the angle of incidence, the band gaps for TM and TE waves behave differently in both ternary and binary lossy structures. The results demonstrate that, by increasing the angle of incidence for the TE wave, the width and the depth of zero-<svg      style="vertical-align:-0.1638pt;width:8.6625004px;" id="M1" height="12.1875" version="1.1" viewBox="0 0 8.6625004 12.1875" width="8.6625004"  xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg">
	
		
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</svg>, zero-<svg     style="vertical-align:-3.56265pt;width:9.5625px;" id="M2" height="12.175" version="1.1" viewBox="0 0 9.5625 12.175" width="9.5625"  xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg">
	
		
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</svg>, and Bragg gap increase in both ternary and binary structures. On the other hand, the enhancement of the angle of incidence for the TM wave contributes to reduction of the width and the depth of the zero-<svg      style="vertical-align:-0.1638pt;width:8.6625004px;" id="M3" height="12.1875" version="1.1" viewBox="0 0 8.6625004 12.1875" width="8.6625004"  xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg">
	
		
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</svg> and Bragg gaps, and they finally disappear for incidence angles greater than 50&#xB0; and 60&#xB0; for the binary structure and 40&#xB0; and 45&#xB0; for the ternary structures, respectively. In addition, the details of the edges of the band gaps variations as a function of incidence angle for both structures are studied.

Alireza Aghajamali

Maryam Akbarimoosavi

Mahmood Barati

Properties of the Band Gaps in 1D Ternary Lossy Photonic Crystal Containing Double-Negative Materials

This paper presents a fast and rigorous design method for grating-based metal-free polarizing filter applications using two-step hybrid optimization techniques. Grating structures utilizing the total internal reflection in a lamellar configuration were used to achieve metal-free solution, which is a key technology in the chirped pulse amplification for high power laser system. Here two polarizing filters were designed: polarization sensitive and polarization insensitive. Those polarization performances were characterized by the rigorous coupled-wave analysis (RCWA), and the design parameters of grating structures, pitch, depth, and filling factor were optimized by two-step hybrid optimization procedure because the diffraction characteristics of grating-based polarizing filters are highly sensitive to small changes in design parameters. The Taguchi method is incorporated into selection process in the genetic algorithm, which indicates that the Taguchi method optimizes the design parameters in a coarse manner, and then, coarsely optimized parameters are finely optimized using the genetic algorithm. Therefore the proposed method could solve global numerical optimization problems with continuous variables. The proposed two-step hybrid optimization algorithm could effectively optimize the grating structures for the purpose of polarization filter applications, and the optimized grating structures could selectively filter the incident light up to 99.8&#x25; as to TE or TM waves.

ChaBum Lee

Total Internal Reflection-Based High Efficiency Grating Design for a Metal-Free Polarizing Filter Applications Using Hybrid Optimization Procedure

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Advances in Optical Technologies