Devices For Optical Networks Research Articles

A magnetically switchable demultiplexer via Terfenol-D in phononic crystal

This study introduces a novel approach for developing a controllable demultiplexer by applying a magnetic field to Terfenol-D cylinders within a solid–solid phononic crystal structure. Dynamic controllable demultiplexers are essential devices in acoustic and optical communication networks, yet adjustable elastic demultiplexers are notably lacking in current sound systems and acoustic communication technologies. The proposed phononic crystal-based demultiplexer features a square lattice (12 × 19) composed of tungsten cylinders embedded in a poly methyl methacrylate (PMMA) substrate. The switchable design consists of two identical, symmetrical parts separated by an input waveguide. In addition, each unit includes an output channel, a common input channel, and a square ring resonator, with the output channel side-coupled to the input bus waveguide. Moreover, Terfenol-D, a magnetostrictive material, is utilized in the hollow cylinders of the output channels. Switchability of the elastic demultiplexer outputs is achieved by dynamically altering the Young’s modulus of the Terfenol-D cylinders through the application of a magnetic field. This magnetic influence modifies the Young’s modulus of the Terfenol-D material in the output waveguides, enabling controllability. By varying the magnetic field applied to the demultiplexer, we find two distinct values of Young’s modulus within the structure. These two values facilitate the high transmission of two desirable peaks with narrow bandwidth through the output channels, allowing for switchable functionality based on the magnetic field’s position. The proposed demultiplexer demonstrates an average crosstalk value of −25.34 dB, indicating strong performance, along with a high average quality factor (Q) of 1773.5 and low average insertion losses of 0.85 dB in the MHz frequency range. The solid–solid elastic controllable demultiplexer is simulated using the finite element method, showcasing its potential for practical applications.

Multimode interference coupler based on general interference for integrated optical and quantum optic devices: a review

Integrated optics play important role in the development for optical network devices, optical processing, instrumentation and quantum information device. Here, multimode interference (MMI) coupler is one of basic component preferred for these integrated optic devices in which MMI coupler based on general interference (GIMMI) has been focused for large scale integrated optic devices because of compact size in comparison to MMI coupler based restricted interference (RIMMI). In this paper, we have reviewed different GIMMI structures reported previously. Different waveguide materials are mentioned and compared for fabrication of GIMMI device. The coupling behaviors and modal analysis of GIMMI couplers and their different tapered structures are estimated by using simple model based on sinusoidal modes showing reduced coupling lengths in down tapered structures in comparison to other structures. The excess loss, polarization dependence loss and crosstalk versus fabrication tolerances are obtained to compare their performances revealing almost same losses and fabrication tolerance. The paper reports the use of the GIMMI coupler in wavelength multiplexing, power splitting, switching, optical processing. Finally, Quantum optic application of GIMMI coupler is shown indicating high quantum fidelity of 50:50 coupling ratio.

Frequency-Shift Monitoring of Optical Filter Based on Optical Labels over FTN-WDM Transmission Systems

Optical network monitoring and soft failure identification such as optical filter shifting and filter tightening are increasingly significant for the complex and dynamic optical networks of the future. Center frequency shift of optical filtering devices in optical networks has a serious impact on the performance of multi-span transmission, especially in high spectrum efficiency faster-than-Nyquist (FTN) transmission systems with various optical switching and add/drop nodes. Existing monitoring schemes generally have the problems of high cost, high complexity, and inability to realize multi-channel online monitoring, which makes it difficult for them to be applied in a wavelength division multiplexing (WDM) system with numerous nodes. In this paper, a monitoring scheme of frequency shift of optical filtering devices based on optical label (OL) is proposed and demonstrated. The signal spectrum of each channel is intentionally divided into many sub-bands with corresponding optical labels loading. The characteristics of spectrum power changing caused by frequency shift can be reflected on labels power changing of each sub-band, which are used to monitor and estimate the value of frequency shift via DSP algorithm. Simulation results show that the monitoring errors of frequency shift can be kept reasonably below 0.5 GHz after 10-span WDM transmission in FTN polarization multiplexing m-ary quadrature amplitude modulation (PM-mQAM) systems. In addition, 250 km fiber transmission experiments are also carried out, and similar results are obtained, which further verify the feasibility of our proposed scheme. The characteristics of low cost, high reliability, and efficiency make it a better candidate for practical application in future FTN-WDM networks.

Semi-embedded slot waveguide electro-optic modulator.

Electro-optic modulators are essential devices on silicon photonic chips in modern optical communication networks. This paper presents a compact, low-loss electro-optic modulator. The modulation efficiency is greatly improved by embedding the lower half of the slot waveguide into the buried oxide layer and inserting graphene at the junction. The interaction of graphene with an optical field in a waveguide is studied using the finite element method. The functions of phase modulation and absorption modulation are realized by changing the gate voltage to change the chemical potential of graphene. The semi-embedded slot waveguide optical modulator has a length of 50µm. After simulation verification, it can be used as an electro-absorption modulator and can achieve a modulation depth of 26.38dB and an insertion loss of 0.60dB. When used as an electro-refractive modulator, it can be realized with a linear change of phase from zero to π; the total insertion loss is only 0.59dB. The modulator has a modulation bandwidth of 79.6GHz, and the energy consumption as electro-absorption and electro-refraction modulation are 0.51 and 1.92pj/bit, respectively. Compared with common electro-optic modulators, the electro-optic modulator designed in this paper has a higher modulation effect and also takes into account the advantages of low insertion loss and low energy consumption. This research is helpful for the design of higher-performance optical communication network devices.

High-sensitivity strain sensor with micron-scale imitation dumbbell structure based on differential temperature self-compensation

A micron-sized dumbbell-like -MZI structure has been developed using hydroxide flame melt taper and arc fusion discharge, with the dumbbell rod region prepared by melt taper drawing and the dumbbell sheet region prepared by arc fusion discharge. This structure has a sensitive light intensity response in the sensing field due to a double-order mode-field coupled excitation region. The geometrical parameters of the dumbbell-like system are optimized theoretically, and the feasibility of the microstructure to achieve high strain sensing sensitivity is analyzed. Experimental results show that the microstructure has a high strain sensing sensitivity of ∼ 0.074 dB/µε and a consistent temperature sensing sensitivity over the entire monitoring wavelength range. Therefore, a light intensity-dependent temperature self-compensation calculation is proposed to achieve a uniform light intensity-strain response for each characteristic peak in the monitored wavelength domain. Since the device has a significant advantage in light intensity modulation and is not affected by polarization light perturbations, it can be used as an alternative light intensity modulation device in optical communication networks and laser research. It can also be used as a probe for medical diagnostic testing based on its enhanced evanescent field properties.

Analysis of GPON capacity by hybrid splitting-ratio base on customer segmentation for Indonesian market during the Covid-19 pandemic

During the Covid-19 pandemic, the impact on internet demand is very high throughout the world. In Indonesia, through a survey conducted, broadband users recorded 175 million people or equivalent to 64 % of the population. Based on field observations, the Passive Optical Network (PON) port utility in the Optical Line Terminal (OLT) is presently below 75 %, as opposed to the initial value, which was more than 95 % [1]. Furthermore, it was also found that more than 80 % of IndiHome customers use a maximum bandwidth of 20 Mbps with majority using 10 Mbps, which is very ineffective, especially related to network capacity. Generally, passive Optical Distribution Network (ODN) devices are not optimally used, therefore this research aims to determine the optimization level of the FTTH network by maximizing the available infrastructure capacity. This process was carried out by increasing the associate ratio of 1:32 to 1:64 while taking into account the Optical Line Terminal (OLT) capacity factor and the standard link budget with schemas A, B and C used to obtain adequate efficiency. Scheme A consists of a 1:2 passive splitter in the Optical Distribution Cabinet (ODC) & 1:32 at the Optical Distribution Point (ODP). Scheme B consists of a 1:4 (ODC) & 1:16 (ODP) passive splitter, while scheme C consists of a 1:8 (ODC) & 1:8 (ODP) passive splitter intended for the use of different customer area types. The result showed an increase in network capacity from 32 to 64 per PON port while taking into account the technical quality of the Link Budget. In conclusion, to ensure this solution functions properly, both simulation and direct measurement tests are carried out using the existing network

Optimization of Gigabit Passive Optical Network (GPON) Devices Replacement Interval

Entering the industrial era that is increasingly advanced and growing, reliable internet connection becomes a very important foundation for every business. Internet connection failure or downtime will be the obstacle and causes much loss both for businessman and for internet provider company. This research aims to find a solution on how to minimize internet connection failure. One of the various methods that can be used to overcome the problem is called preventive maintenance. This research is chosen to determine how far the role of preventive maintenance in reducing the risk of connection failure due to device failure. Several tools that used in this research, such as statistical distribution to determine the pattern of device failure, and mathematical formula to calculate the estimated duration of the downtime occurs based on the time of preventive maintenance was applied. From that calculation, it can be concluded the optimal time to apply preventive maintenance to minimize downtime duration. The results reveal that a decreasing downtime value happens when preventive maintenance is applied at the optimal age of the device. EI8E - 8FE Electrical Interface Card kit was reduced by 8.01% with an optimal age of 21.82 days. GTGH - 16 Port GPON Line Card devices were reduced by 5.46% with an optimal age of 16.69 days. EMTPDP-DC Power Board devices are reduced by 0.1% with an optimal age of 53 days. The GPON MSVG - Control & Switching Card device is reduced by 4.38% with an optimal age of 32.28 days. MTPD - Power Supply equipment is reduced by 1.2% with an optimal age of 92.35 days. The ETC8B - 8E1 / T1 CES Card device was reduced by 0.84% with an optimal age of 41.23 days.

Optical Cable Backbone Network Design In The Province Kalimantan East Use Technology DWDM OTN

In designing the backbone network for the province of East Kalimantan using Dense Wavelength Division Multiplexing (DWDM) and Optical Transport Network (OTN) devices which cover 10 districts and cities consisting of 34 segments, of which 34 segments consist of 10 OTN DWDM sites and 16 Optical Land Amplifier sites ( OLA). From the results of the design and simulation of the backbone network, it was found that the value of the Optical Link Power Budget (OLPB) < 50 dBm where this value is the ideal value in deploying a DWDM OTN backbone network, and the range of the Optical Signal Noise Ratio (OSNR) is between 20 dBm < OSNR < 40 dBm, which is the ideal value for OSNR, and has an Optical Rise Time Budget (ORTB) < 60 ps, and also has a segment margin system of > 7 dB.

Optical Cable Backbone Network Design In The Province Kalimantan Middle Use Technology DWDM OTN

In designing the backbone network for the province of East Kalimantan using Dense Wavelength Division Multiplexing (DWDM) and Optical Transport Network (OTN) devices which cover 10 districts and cities consisting of 34 segments, of which 34 segments consist of 10 OTN DWDM sites and 16 Optical Land Amplifier sites ( OLA). From the results of the design and simulation of the backbone network, it was found that the value of the Optical Link Power Budget (OLPB) < 50 dBm where this value is the ideal value in deploying a DWDM OTN backbone network, and the range of the Optical Signal Noise Ratio (OSNR) is between 20 dBm < OSNR < 40 dBm, which is the ideal value for OSNR, and has an Optical Rise Time Budget (ORTB) < 60 ps, and also has a segment margin system of > 7 dB.

Optical Cable Backbone Network Design In The Province Kalimantan South Use Technology DWDM OTN

In designing the backbone network for the province of East Kalimantan using Dense Wavelength Division Multiplexing (DWDM) and Optical Transport Network (OTN) devices which cover 10 districts and cities consisting of 34 segments, of which 34 segments consist of 10 OTN DWDM sites and 16 Optical Land Amplifier sites ( OLA). From the results of the design and simulation of the backbone network, it was found that the value of the Optical Link Power Budget (OLPB) < 50 dBm where this value is the ideal value in deploying a DWDM OTN backbone network, and the range of the Optical Signal Noise Ratio (OSNR) is between 20 dBm < OSNR < 40 dBm, which is the ideal value for OSNR, and has an Optical Rise Time Budget (ORTB) < 60 ps, and also has a segment margin system of > 7 dB.

Optical Cable Backbone Network Design In The Province Kalimantan North Use Technology DWDM OTN

In designing the backbone network for the province of East Kalimantan using Dense Wavelength Division Multiplexing (DWDM) and Optical Transport Network (OTN) devices which cover 10 districts and cities consisting of 34 segments, of which 34 segments consist of 10 OTN DWDM sites and 16 Optical Land Amplifier sites ( OLA). From the results of the design and simulation of the backbone network, it was found that the value of the Optical Link Power Budget (OLPB) < 50 dBm where this value is the ideal value in deploying a DWDM OTN backbone network, and the range of the Optical Signal Noise Ratio (OSNR) is between 20 dBm < OSNR < 40 dBm, which is the ideal value for OSNR, and has an Optical Rise Time Budget (ORTB) < 60 ps, and also has a segment margin system of > 7 dB.

Data-Taking Network for COMET Phase-I

An experiment to search for mu-e conversion named COMET is being constructed at J-PARC. The experiment will be carried out using a two-stage approach of Phase-I and Phase-II. The data taking system of Phase-I is developed based on common network technology. The data taking system consists of two kinds of networks. One is a front-end network. Its network bundles around twenty front-end devices that have a 1-Gb optical network port. And a front-end computer accepts data from the devices via its network. The other is a back-end network that collects all event fragments from the front-end computers using a 10-Gb network. We used a low price 1Gb/10Gb optical network switch for the front-end network. And direct connection between the front-end PC and an event building PC using 10-Gb optical network devices was used for the back-end network. The event building PC has ten 10-Gb network ports. And each network port of the event building PC is connected to the front-end PC's port without using a network switch. We evaluated data taking performance with an event building on these two kinds of networks. The event building throughput of the front-end network achieved 337 MiB/s. And the event building throughput of the back-end networks achieved 1.2 GiB/s. It means that we could reduce the construction cost of the data taking network using this structure without deteriorating performance. Moreover, we evaluated the writing speed of the local storage RAID disk system connected to a back-end PC by a SAS interface, and a long-distance network copy from the experiment location to the lasting storage.

Multimode Interference Induced Optical Routing in an Optical Microcavity

AbstractThe photonic router is a key device in optical communication and quantum networks. Here, the results of a study of multi‐channel optical routing using optomechanical multimode interference in an optical microcavity are reported. The optomechanical system used here exhibits multi‐optical modes and a mechanical mode. Optomechanical induced transparency and absorption appear in the system due to the interference between different paths. It is shown that the system can be served as a three‐port routing in the red‐detuned region to rout photons from the input port to an arbitrarily selected output port with high routing efficiency by controlling the parameters corresponding to different interference paths.

On-Chip Programmable Nonlinear Optical Signal Processor and Its Applications

We introduce an integrated device based on microring resonator (MRR) assisted Mach-Zehnder interferometer (MZI) preceded by a tunable MZ coupler for nonlinear optical signal processing. The novel structure of this device provides both high programmability and switching contrast. These desirable features suggest its potential use as a multi-purpose optical processor providing different high-performance functionalities. We experimentally demonstrate two functionalities using the same device fabricated on a silicon-on-insulator substrate. One functionality is an all-optical thresholder enabling 40× signal contrast improvement, and the other functionality is clock-less pulse carving technique that converts long-pulse signals to short-pulse signals. With these functionalities, we discuss system-level applications of our device in optical interconnects and photonic neural networks.

Optical Cable Backbone Network Design in West Kalimantan Province Using OTN DWDM Technology

In designing the backbone network for the province of West Kalimantan using Dense Wavelength Division Multiplexing (DWDM) and Optical Transport Network (OTN) devices which cover 14 districts and cities consisting of 30 segments, of which 30 segments consist of 14 DWDM OTN sites and 8 Optical Land Amplifier sites ( OLA). From the results of the design and simulation of the backbone network, it was found that the value of the Optical Link Power Budget (OLPB) < 50 dBm where this value is the ideal value in deploying a DWDM OTN backbone network, and the range of the Optical Signal Noise Ratio (OSNR) is between 20 dBm < OSNR < 40 dBm, which is the ideal value for OSNR, and has an Optical Rise Time Budget (ORTB) < 60 ps, and also has a segment margin system of > 7 dB.

Methodology and Software Tool for Energy Consumption Evaluation and Optimization in Multilayer Transport Optical Networks

In communication networks, the volume of traffic, the number of connected devices and users continues to grow. As a result, the energy consumption generated by the communication infrastructure has become an important parameter that needs to be carefully considered and optimized both when designing the network and when operating it in real-time. In this paper, the methodology of calculation of complex parameters of energy consumption for transport telecommunication networks is proposed. Unlike the known techniques, the proposed methodology takes into account heterogeneity and multilayer networks. It also takes into account the energy consumption parameter during the downtime of the network equipment in the process of processing the service data blocks, which is quite an important task for improving the accuracy of energy consumption at the stage of implementing the energy-saving network. We also developed simulation software to estimate and manage the energy consumption of the optical transport network using the LabVIEW environment. This software tool allows telecommunication network designers to evaluate energy consumption, which allows them to choose the optimal solution for the desired projects. The use of electro-and acousto-optical devices for optical transport networks is analyzed. We recommended using electro-optical devices for optical modulators and acousto-optical devices for optical switches. The gain from using this combination of optical devices and the parameter of rij electro-optical coefficient and M2 acousto-optical quality parameter found in the paper is about 36.1% relative to the complex criterion of energy consumption.

Electromagnetically induced grating with second field quantization in spherical semiconductor quantum dots

A new approach for diffracting the weak probe beam into higher-order directions is proposed via electromagnetically induced grating in second field quantization formalism, offering a new way for implementations of quantum information with semiconductor quantum dots. The formalism of second field quantization allows describing atoms and photons as a many-body system. An induced diffraction grating is formed based on the electromagnetic induced transparency when a standing-wave coupling field is applied to a spherical quantum dot as a three-level system. Due to phase modulation, the zeroth-order light intensity becomes weak, and the first-order diffraction is improved affectedly. On the contrary, the probe beam is barely diffracted via absorption modulation. The simulation results verify that photon numbers of probe and control fields, as well as other parameters in the QD, can lead to the diffraction efficiency of phase grating to be improved. Phase diffraction grating accompanied with a high transmissivity is demonstrated, and the first-order diffraction efficiency reaches $$30\%$$. Also, the impact of QD dimensions on its optical response is investigated. This model may find potential applications in designing the semiconductor quantum dot-based photonic devices in optical communications and quantum information networks.

A Single-Photon Switch with Two Quantum Emitters in One-Dimensional Coupled-Resonator Waveguides

Nowadays, the quantum switch is playing a key device in optical quantum networks. In this paper, we investigate the transport of a single photon in one-dimensional coupled-resonator waveguides with two quantum emitters, which the first quantum emitter fixed at x = 0 and the other can be placed at any position. The numerical results show that the transport properties of the single-photon are particularly sensitive to the position of the second quantum emitter. The coupling strength of gn can broaden the width of the transmission spectra, the larger the coupling strength gn is, the wider transmission spectra is. Not only that, single-photon in the controllable channel can be perfectly reflected or transmitted by the quantum emitter. We also found that if both two quantum emitters are embedded at x = 0, the dipole-dipole interactions of two quantum emitters can change the dip positions in the spectra.

A DEVELOPMENT OF OPTICAL NETWORK UNIT POWER CONSUMPTION MODEL CONSIDERING TRAFFIC LOAD EFFECT

Accurate and precise measurement of energy consumption for the deployment of fiber-to-the-home (FTTH) network using Gigabit passive optical network (GPON) is vital to the research community to develop models for the synthesis of energy-efficient protocols and algorithms for the access network. However, lack of power consumption measurement of optical network devices in the past has led to unrealistic and/or oversimplified model being used in simulations. Usually the access network devices are assumed always on and their consumption is both traffic and time independent. Therefore, in this paper we propose an experimentally-driven approach to i) characterize the Optical Network Unit (ONU) from the power consumption standpoint and ii) develop more accurate power consumption model for the ONU. We focus on ONU since it represents the main contributor to the energy consumption of optical access network. The real data in terms of the power consumption and traffic load have been obtained from continuous measurements performed on a GPON network testbed. The measurement is limited to a maximum 100 Mbps data rate due to a limitation in the sampling rate and precision of the measurement device. However, validation has been done with theoretical power consumption model in order to prove the feasibility of the proposed model. Our measurements show that the power consumption of the ONU exhibits a linear dependence on the traffic in which the power consumption at idle mode is 11.51 W while in low power mode the power consumption is around 7.52 W.

Targeted photonic routers with chiral photon-atom interactions

The photonic router is a key device in optical quantum networks. Conventional routers, however, can only transfer a photon from the input port to the desired port probabilistically. Here, we propose to use chiral photon-atom interactions for targeted routing that can transfer a single photon from the input port to an arbitrarily selected output port deterministically, i.e., with $100%$ probability. The configuration of the proposed router consists of a driven three-level atom which is chirally coupled to two photonic waveguides simultaneously. It is shown that, by properly adjusting the driving field on the atom, a single photon inputting from one port of the first waveguide can be deterministically transferred to one of the selected output ports of the second waveguide. Both resonant and nonresonant photons can be deterministically routed to the desired ports. We also examine how the routing fidelity is influenced by dissipations and imperfections, and investigate the transmission characters of two resonant photons.