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Abstract

VTT Technical Research Centre of Finland Ltd. has developed and utilized Low Temperature Co-fired Ceramic (LTCC) technology for about 25 years. This paper presents our activities related to photonics and millimetre-waves, including also a relevant literature survey. First a short summary of the technology is given. Especially, the unique features of LTCC technology are described in more details. In addition, several examples have been given to show the validity of LTCC technology in these high-performance fields.

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Authors and Affiliations

Markku Lahti
Kari Kautio
Mikko Karppinen
Kimmo Keränen
Jyrki Ollila
Pentti Karioja
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Abstract

In this work studies on propagation properties of a microstructured polymer optical fibre infiltrated with a nematic liquid crystal are presented. Specifically, the influence of an infiltration method on the LC molecular alignment inside fibre air-channels and, thus, on light guidance is discussed. Switching between propagation mechanisms, namely the transition from modified total internal reflection (mTIR) to the photonic bandgap effect obtained by varying external temperature is also demonstrated.

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Authors and Affiliations

K.A. Rutkowska
K. Milenko
O. Chojnowska
R. Dąbrowski
T.R. Woliński
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Abstract

In article a two-dimensional photonic crystal (PhC) is considered and modelled as a new generation antireflection coating for optoelectronic devices. Traditional antireflective coatings (ARCs) reduce the reflection of the radiation only – the new generation of antireflective coatings should affect the distribution of the radiation also. Such functionality can be provided by the two-dimensional PhC which reduce the reflection and scatter transmitted light. Prior to the fabrication, the PhCs should be designed and analysed. Results of the analysis should provide quantitative means for choice of materials and design solutions. In work, we analyse the electromagnetic field distribution as Poynting vectors inside the materials of optoelectronic devices, in order to investigate the possibility of improving the construction of future optoelectronic devices. Furthermore, we calculate the reflection and transmission of that ARC. It’s a complex optic analysis of new generation of ARC. The numerical analysis has been performed with the FDTD method in Lumerical Software. In work, we consider the two-dimensional photonic crystal on the top surface of optoelectronic structures. We compared the results with the traditional ARC from these same parameters as PhC: thickness and material. As an example, we presented the application of modelled, photonic crystal, thin-film, GaAs solar cells with PhC on top. The efficiency of this solar cell, using the photonic crystal, was improved by 6.3% over the efficiency of this same solar cell without PhC. Thus, our research strongly suggests that the unique properties of the photonic crystal could be used as a new generation of ARC.

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Authors and Affiliations

D. Przybylski
S. Patela
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Bibliography

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Authors and Affiliations

Mahesh V. Sonth
1
G. Srikanth
1
Pankaj Agrawal
1
B. Premalatha
2

  1. Department of Electronics and Communication Engineering, CMR Technical Campus, Hyderabad-501401, Telangana, India
  2. Department of Electronics and Communication Engineering, CMR College of Engineering & Technology, Hyderabad-501401,Telangana, India
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Abstract

This paper comprehensively presents key issues in design of an original optoelectronic measurement device built to assess amount of suspended particulate matter. The paper is introduced with a short explanation of concerns with a suspended particulate matter, what role it has in the air quality and how it affects health of human population. Then, problems of construction of the measurement device supported by a theoretical explanation on the basis of Mie theory are discussed. Subsequently, it is followed by an analysis of the device operation both in laboratory and in real conditions. Results obtained with the presented device are compared with the professional measurement equipment and an expensive, outdoor measurement station. Paper is concluded with observations of differences in spatio-temporal PM change at very close but significantly different city locations.

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Authors and Affiliations

L. Makowski
B. Dziadak
M. Suproniuk
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Abstract

Two highly sensitive optical sensor topologies are proposed and simulated in this paper. The proposed structures are optimized to provide better performance characteristics such as sensitivity, detection limit, and quality factor. They are based on two-dimensional photonic crystals consisting of rectangular arrays of GaAs rods in SiO2 substrates. Such lattices have bandgaps for transverse magnetic modes. Two-dimensional finite difference time domain and plane wave expansion methods are used for the simulation and analysis of the refractive index sensors and particle swarm optimization method is used to optimize the structural parameters. The designed structures show a high sensitivity to refractive index variations. They are able to detect refractive indices from 1.33 to 1.5. An excellent figure of merit equal to 737 RIU−1 is observed for the proposed structure and a significant improvement is observed compared to the structures reported in the literature.

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Authors and Affiliations

F. Rahman-Zadeh
M. Danaie
H. Kaatuzian
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Abstract

Optical waveguides (WGs) are widely used as interconnects in integrated optical circuits both for telecommunication and sensing applications. There are different kind of optical WG designs that offers different guiding parameters, opening a vast number of possibilities. A silica-titania (SiO2:TiO2) rib WG is discussed and examined by a numerical analysis in this article with a great emphasis on the analysis of bending losses and optimization. A modal analysis for different basic parameters of the WG is presented with a detailed wavelength-based modal analysis. Various potential fabrication methods are discussed, however, a sol-gel method and dip-coating deposition technique are proposed for the low-cost development of such WGs. Moreover, an approach towards minimizing the bending losses by adding an upper cladding layer on the rib WG is presented and described.
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Authors and Affiliations

Muhammad Shahbaz
1
ORCID: ORCID
Łukasz Kozlowski
1
Muhammad A. Butt
1
ORCID: ORCID
Ryszard Piramidowicz
1
ORCID: ORCID

  1. Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warszawa, Poland
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Abstract

Propagation of linearly polarized light beams in a nematic liquid crystal cell with distinguished regions of different molecular orientation has been analyzed. Specifically, combination of the planar/homogenic and homeotropic alignment, forming thus spatially limited regions characterized by a different LC molecular orientation, has been tested, as achieved by means of the photo-orientation and photo-polymerization processes, independently. An influence of molecular orientation on the light beam propagation has been checked for different directions of the linear polarization. Thanks to the molecular reorientation induced by the low frequency external electric field and also to the reorientational nonlinearity taking place in NLCs, propagation direction of the light beam can be additionally controlled by the electric bias and/or optical power, respectively. Proposed structural solutions and techniques, related to the photo-orientation and photo-polymerization processes described in this communication, give rise to the novel LC geometries and structures. The latter act as promising candidates for new practical photonic applications as they are expected to be of a particular importance for integrated optic elements and devices.

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Authors and Affiliations

K.A. Rutkowska
M. Chychłowski
M. Kwaśny
I. Ostromęcka
J. Piłka
U.A. Laudyn
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Abstract

In this paper analyses of mode distribution, confinement and experimental losses of the photonic crystal fibers with different core sizes infiltrated with liquid crystal are presented. Four types of fibers are compared: with single-, seven-, nineteen- and thirty seven solid rods forming the core in the same hexagonal lattice of seven “rings” of unit cells (rods or capillaries). The experimental results confirming the influence of the core diameter on light propagation are also included. The diameter of cores determines not only the number of modes in the photonic liquid crystal fiber but also is correlated with experimentally observed attenuation. For fibers with larger cores confinement losses are expected to be higher, but the measured attenuation is smaller because the impact of liquid crystal material losses and scattering is smaller.

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Authors and Affiliations

M.M. Sala-Tefelska
S. Ertman
T.R. Woliński
P. Mergo
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Abstract

We present the results of a numerical analysis of a two-dimensional photonic crystal with line defect for a laser gas sensor working in a slow light regime. The geometrical parameters of photonic crystals with three different line defects were numerically analyzed: a missing row of holes, a row of holes with changed diameter and air channel. Antireflection sections were also analyzed. The simulations were carried out by MEEP and MPB programs, with the aim to get the values of a group refractive index, transmission and a light-gas overlap as high as possible. The effective refractive index method was used to reduce the simulation time and required computing power. We also described numerical simulation details such as required conditions to work in the slow light regime and the analyzed parameters values’ dependency of the simulation resolution that may influence the accuracy of the results.

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Authors and Affiliations

A. Zakrzewski
S. Patela
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Abstract

An optimal design of a slot waveguide is presented for realizing an ultrafast optical modulator based on a 220 nm silicon wafer technology. The recipe is to maximize the confinement and interaction between optical power supported by the waveguide and electric field applied through metallic electrodes. As height of waveguide is fixed at 220 nm, the waveguide and slot width are optimized to maximize the confinement factor of optical power. Moreover, metal electrodes tend to make the waveguide lossy, their optimal placement is calculated to reduce the optical loss and enhance the voltage per unit width in the slot. Performance of an optimally designed slot waveguide with metal electrodes as ultrafast modulator is also discussed.

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Authors and Affiliations

N. Malviya
V. Priye
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Abstract

A ternary photonic crystal with left-handed material (LHM) layer is examined for refractometric applications. One of the layers is assumed to be air and treated as an analyte. The transmittance from the ternary photonic crystal is studied in details and the wavelength shift due to the change in the refractive index of the analyte is investigated. The transmittance is investigated with the parameters of the LHM. It is found that the wavelength shift can be significantly enhanced with the decrease of both real part of the LHM permittivity and thickness.

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Authors and Affiliations

S.A. Taya
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Abstract

The aim of this work was to induce permanent birefringence both in typical liquid crystal cells and photonic crystal fibers (PCFs) by photo-polymerization. For this purpose three different liquid crystalline materials, namely E7, 5CB, and 6CHBT were combined with a mixture of RM257 monomer and a UV sensitive initiator with the percentage weight less than 10%. Due to the photo-polymerization process it was possible to achieve polymer-stabilized liquid crystal orientation inside LC cells and micro-sized cylindrical glass tubes. In particular, periodic change in spatial molecular orientation was achieved by selective photo-polymerization. Successful results obtained in these simple geometries allowed for the experimental procedure to be repeated in PCFs leading to locally-induced permanent birefringence in PCFs.

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Authors and Affiliations

M.S. Chychłowski
S. Ertman
K. Rutkowska
O. Strzeżysz
R. Dąbrowski
T.R. Woliński
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Abstract

Structural health monitoring of aircraft assures safety, integrity and reduces cost-related concerns by reducing the number of times maintenance is required. Under aerodynamic loading, aircraft is subjected to strain, in turn causing damage and breakdown. This paper presents a review of experimental works, which focuses on monitoring strain of various parts of aircraft using optical fibre sensors. In addition, this paper presents a discussion and review on different types of optical fibre sensors used for structural health monitoring (SHM) of aircraft. However, the focus of this paper is on fibre bragg gratings (FBGs) for strain monitoring. Here, FBGs are discussed in detail because they have proved to be most viable and assuring technology in this field. In most cases of strain monitoring, load conditioning and management employs finite element method (FEM). However, more effort is still required in finding the accurate positions in real time where the sensors can be placed in the structure and responds under complex deformation.
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Authors and Affiliations

Monica Murthy N
1
Priyanka Desai Kakade
2

  1. Manipal Institute of Technology, Manipal Academy of Higher Education, India
  2. Department of Electronics and Communication Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka, India
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Abstract

This work suggests a brand-new 1*4 two-dimensional demultiplexer design based on multicore photonic crystal fiber. Numerical models show that the optical signals can be separated in a photonic crystal fiber construction using optical signals with wavelengths of 0.85, 1.1, 1.19, and 1.35 μm injected on the center core and separated into four cores. The innovative design switches different air-hole positions using pure silica layers throughout the length of the fiber to regulate the direction of light transmission between layers.
Wavelength demultiplexers are essential parts of optical systemic communications. They serve as a data distributor and can use a single input to produce multiple outputs. The background material is frequently natural silica, and air holes can be found anywhere throughout the length of the fiber as the low-index components.
The simulation results showed that after a 6 mm light propagation, the four-channel demux can start to demultiplex.
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Authors and Affiliations

Assia Ahlem Harrat
1
Mohammed Debbal
1
Mohammed Chamse Eddine Ouadah
2

  1. Department of Electronics and Telecommunications, Faculty of Science and Technology, University of Belhadj Bouchaib, Algeria
  2. Department of Telecommunications, Faculty of Electrical and Computer Engineering, University of Mouloud Mammeri, Algeria
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Abstract

New optimized 2x2 slotted array antenna is designed using HFSS to operate at 28.1 GHz, using RT6010 substrate with height of 1.6 mm, tangent loss of 0.0023 and dielectric constant of 10.2 and overall dimension of 12x12 mm2, for 5G mobile applications. The 2x2 slotted linear array antenna achieved a high gain of 18.3 dB at 28.1 GHz with 10 dB bandwidth of 1.39 GHz, and with 83.21% of size reduction.

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Authors and Affiliations

Shaikh Rehan Haneef
Sathish Kumar Selvaperumal
Vikneswary Jayapal
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Abstract

WILGA annual symposium on advanced photonic and electronic systems has been organized by young scientist for young scientists since two decades. It traditionally gathers around 400 young researchers and their tutors. Ph.D students and graduates present their recent achievements during well attended oral sessions. Wilga is a very good digest of Ph.D. works carried out at technical universities in electronics and photonics, as well as information sciences throughout Poland and some neighboring countries. Publishing patronage over Wilga keep Elektronika technical journal by SEP, IJET and Proceedings of SPIE. The latter world editorial series publishes annually more than 200 papers from Wilga. Wilga 2018 was the XLII edition of this meeting. The following topical tracks were distinguished: photonics, electronics, information technologies and system research. The article is a digest of some chosen works presented during Wilga 2018 symposium. WILGA 2017 works were published in Proc. SPIE vol.10445. WILGA 2018 works were published in Proc. SPIE vol.10808.
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Authors and Affiliations

Ryszard S. Romaniuk
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Abstract

Hybrid pixel radiation detectors with a direct photon-to-charge conversion working in a single photon counting mode have gained increasing attention due to their high dynamic range and noiseless imaging. Since sensors of different materials can be attached to readout electronics, they enable work with a wide range of photon energies. The charge-sharing effect observed in segmented devices, such as hybrid pixel detectors, is a phenomenon that deteriorates both spatial resolution and detection efficiency. Algorithms that allow the detection of a photon irrespective of the charge-sharing effect are proposed to overcome these limitations. However, the spatial resolution of the detector can be further improved beyond the resolution determined by the pixel size if information about the charge proportions collected by neighbouring pixels is used to approximate the interaction position. In the article, an approach to achieve a subpixel resolution in a hybrid pixel detector working in the single photon counting mode is described. Requirements and limitations of digital inter-pixel algorithms which can be implemented on-chip are studied. In the simulations, the factors influencing the detector resolution are evaluated, including size of a charge cloud, number of virtual pixel subdivisions, and detector parameters.
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Bibliography

  1. Ballabriga, et al. Review of hybrid pixel detector readout ASICs for spectroscopic X-ray imaging. J. Instrum. 11, P01007–P01007 (2016). https://doi.org/10.1088/1748-0221/11/01/P01007
  2. Taguchi, K. & Iwanczyk, J. S. Vision 20/20: Single photon counting X-ray detectors in medical imaging. Med. Phys. 40, 100901 (2013). https://doi.org/10.1118/1.4820371
  3. Bahadur, D. et al. Evolution of structure and dynamics of thermo-reversible nanoparticle gels-A combined XPCS and rheology study. J. Chem. Phys. 151, 10 (2019). https://doi.org/10.1063/1.5111521
  4. Sheyfer, et al.Nanoscale critical phenomena in a complex fluid studied by X-ray photon correlation spectroscopy.Phys. Rev. Lett. 125, 125504 (2020). https://doi.org/10.1103/PhysRevLett.125.125504
  5. Szczygiel, R., Grybos, P., Maj, P. & Zoladz, M. PXD18k - Fast Single Photon Counting Chip with Energy Window for Hybrid Pixel Detector. in 2011 IEEE Nuclear Science Symposium Conference Record. 932–937 (IEEE, Valencia, Spain 2011). https://doi.org/10.1109/NSSMIC.2011.6154126
  6. Nilsson, H. E., Dubari, E., Hjelm, M. & Bertilsson, K. Simulation of photon and charge transport in x-ray imaging semiconductor sensors. Nucl. Instrum. Methods Phys. Res. A. 487, 151–162 (2002). https://doi.org/10.1016/S0168- 9002(02)00959-2
  7. Ballabriga, R. et al. The Medipix3RX: a high resolution, zero dead-time pixel detector readout chip allowing spectroscopic imaging. Instrum. 8, C02016–C02016 (2013). https://doi.org/10.1088/1748-0221/8/02/C02016
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  11. Otfinowski, P., Deptuch, G. W. & Maj, P. Asynchronous approximation of a center of gravity for pixel detectors’ readout circuits. IEEE Solid-State Circuits 53, 1550–1558 (2018). https://doi.org/10.1109/JSSC.2018.2793530
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Authors and Affiliations

Aleksandra Krzyżanowska
1
ORCID: ORCID
Robert Szczygieł
1
ORCID: ORCID

  1. AGH University of Science and Technology, 30 A. Mickiewicza Ave., 30-059 Krakow, Poland
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Abstract

In this paper, triangular lattice index-guiding photonic crystal fibres (PCFs) are synthesized to compensate the chromatic dispersion of a single mode fibre (SMF-28) for an 80 km optical link operating at 1.55 μm, by using a directed tabu search algorithm. Hole-to-hole distance, circular air-hole diameter, solid-core diameter, ring number and PCF length parameters are optimized for this purpose. Three synthesized PCFs with different physical parameters are compared in terms of their objective functions values, residual dispersions, compensation ratios and confinement losses.

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Authors and Affiliations

Fethallah Karim
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Abstract

Recent years, the design of photonic crystal (PC) based optical devices is receiving keen interest in research and scientific community. In this paper, two dimensional (2D) PC based eight channel demultiplexer is proposed and designed and the functional characteristics of demultiplexer namely resonant wavelength, transmission efficiency, quality factor, spectral width, channel spacing and crosstalk are investigated. The demultiplexer is designed to drop the wavelength centred at 1537.6 nm, 1538.5 nm, 1539.4 nm, 1540.4 nm, 1541.2 nm, 1541.9 nm, 1542.6 nm and 1543.1 nm. The proposed demultiplexer is primarily composed of bus waveguide, drop waveguide and quasi square ring resonator. The quasi square ring resonator and square ring micro cavity (inner rods) are playing a vital role for a desired channel selection. The operating range of the devices is identified through a photonic band gap (PBG) which is obtained using a plane wave expansion (PWE) method. The functional characteristics of the proposed demultiplexer are attained using a 2D finite difference time domain (FDTD) method. The proposed device offers low crosstalk and high transmission efficiency with ultra-compact size, hence, it is highly desirable for DWDM applications.

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Authors and Affiliations

V. Kannaiyan
R. Savarimuthu
S.K. Dhamodharan
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Abstract

Thermo-optic properties enhancement of the bi-stable temperature threshold sensors based on a partially filled photonic crystal fiber was reported. Previously tested transducers filled with a selected group of pure n-alkanes had in most cases differences between switching ON and OFF states. Therefore, the modification of filling material by using additional crystallization centers in the form of gold nanoparticles was applied to minimize this undesirable effect. The evaluation of the thermodynamic properties of pentadecane and its mixtures with 14 nm spherical Au nanoparticles based on the differential scanning calorimetry measurements was presented. Optical properties analysis of sensors prepared with these mixtures has shown that they are bounded with refractive index changes of the filling material. Particular sensor switches ON before melting process begins and switches OFF before crystallization starts. Admixing next group of n-alkanes with these nanoparticles allows to design six sensors transducers which change ON and OFF states at the same temperature. Thus, the transducers with a wider temperature range for fiber-optic multi-threshold temperature sensor tests will be used.

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Authors and Affiliations

N. Przybysz
P. Marć
E. Tomaszewska
J. Grobelny
L.R. Jaroszewicz
ORCID: ORCID
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Abstract

We describe a new method to separate ballistic from the scattered photons for optical tissue characterization. It is based on the hypothesis that the scattered photons acquire a phase delay. The photons passing through the sample without scattering or absorption preserve their coherence so they may participate in interference. We implement a Mach−Zehnder experimental setup where the ballistic photons pass through the sample with the delay caused uniquely by the sample indices of refraction. We incorporate a movable mirror on the piezoelectric actuator in the sample arm to detect the amplitude of the modulation term. We present the theory that predicts the path−integrated (or total) concentration of the scattering and absorption centres. The proposed technique may characterize samples with transmission attenuation of ballistic photons by a factor of 10-14.

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Authors and Affiliations

F. Corral
M. Strojnik
G. Paez
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Abstract

In this attempt, Two Dimensional Photonic Crystal (2DPC) Quasi Square Ring Resonator (QSRR) based four channel demultiplexer is proposed and designed for Wavelength Division Multiplexing systems. The performance parameters of the demultiplexer such as transmission efficiency, passband width, line spacing, Q factor and crosstalk are investigated. The proposed demultiplexer is composed of bus waveguide, drop waveguide and QSRR. In the proposed demultiplexer, the output ports are arranged separately in odd and even number, where an odd number of ports are located on the right side and even number of ports are located on the left side of the bus waveguide that are used to reduce the channel interference or crosstalk. Further, the refractive index of rods around the center rod is increased linearly one to another in order to improve the signal quality. The resonant wavelengths of the proposed demultiplexer are of 1521.1 nm, 1522.0 nm, 1523.2 nm and 1524.3 nm, respectively. The footprint of the device is of 180.96 μm2. Then, a four channel point to point network is designed and the proposed four channel demultiplexer is implemented by replacing a conventional demultiplexer. Finally, functional parameters of the network, namely, BER, receiver sensitivity and Q factor are estimated by varying the link distance. This attempt could create new dimensions of research in the domain of photonic networks.

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Authors and Affiliations

V. Kannaiyan
R. Savarimuthu
S.K. Dhamodharan
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Abstract

All normal dispersion (ANDi) and highly nonlinear chalcogenide glass photonic crystal fiber (PCF) is proposed and numerically investigated for a broad, coherent and ultra-flat mid-infrared supercontinuum generation. The proposed PCF consists of a solid core made of Ga8Sb32S60 glass surrounded by seven rings of air holes arranged in a triangular lattice. We show by employing the finite difference frequency domain (FDFD) method that the Ga8Sb32S60 PCF dispersion properties can be engineered by carefully adjusting the air holes diameter in the cladding region and ANDi regime is achieved over the entire range of wavelengths with a zero chromatic dispersion around 4.5 μm. Moreover, we demonstrate that injecting 50 fs width and 20 kW peak power laser pulses (corresponding to a pulse energy of 1.06 nJ) at a pump wavelength of 4.5 μm into a 1 cm long ANDi Ga8Sb32S60 PCF generates a broad, flat-top and perfectly coherent SC spectrum extending from 1.65 μm to 9.24 μm at the 20 dB spectral flatness. These results make the proposed Ga8Sb32S60 PCF an excellent candidate for various important mid-infrared region applications including mid-infrared spectroscopy, medical imaging, optical coherence tomography and materials characterization.

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Authors and Affiliations

A. Medjouria
D. Abedb
Z. Becera

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