Optimization of Parameters for Optimal Performance

2015 ◽  
pp. 272-284
Keyword(s):  
Spectral Density ◽  
Wavelength Division Multiplexing ◽  
Duty Cycle ◽  
Optical Filter ◽  
Spectral Width ◽  
Optical Signal ◽  
Signal Pulse ◽  
Filter Bandwidth ◽  
Wavelength Division ◽  
Optical Time

The impact of the signal pulse width and the optical filter bandwidth on the performance of both RZ and NRZ On-Off Keying (OOK) Optical Time Division Multiplexing (OTDM)-Wavelength Division Multiplexing (WDM) systems are studied in this chapter. Using polynomial fitting, an approximated expression for the optimal signal pulse duty cycle as a function of the spectral density SD and Optical Signal to Noise Ratio (OSNR) is provided. Further, it is found that the bit rate per WDM channel does not affect the optimum signal pulse duty cycle. As the spectral density SD increases, DCopt increases, reducing the signal spectral width to compensate for the reduced the WDM channel frequency spacing ?f. For increasing OSNR, DCopt increases slightly, especially at higher SD. The authors found that ideal NRZ performs better than optimized RZ at high SD but worse at low SD.

Impact of a Post-OTDM-Demux Optical Filter

2015 ◽  
pp. 310-325
Keyword(s):  
Wavelength Division Multiplexing ◽  
Pulse Width ◽  
Optical Filter ◽  
Signal Pulse ◽  
Spectral Densities ◽  
Wavelength Division ◽  
Optical Time Division Multiplexing ◽  
Optical Time ◽  
Time Division ◽  
The Impact

The impact of a post-OTDM-demultiplexing optical filter on the performance of dense On-Off Keying (OOK) Optical Time Division Multiplexing (OTDM)-Wavelength Division Multiplexing (WDM) systems is studied in this chapter. For Return-to-Zero (RZ) modulation, it was found that the additional filter working in a double-tier filter configuration did not offer any significant improvements to performance when the signal pulse width is optimized. Improvements generally increase only when the signal pulse width deviates from its optimal value and only for low spectral densities. For ideal Non-Return-to-Zero (NRZ) modulation, however, significant improvements of around 1 dB are obtained using the double-tier configuration over a large range of spectral densities.

scholarly journals A Pulse Shaping Based Optical Transmission System of 128QAM for DWDM with N × 904 Gbps

2019 ◽  
Vol 9 (5) ◽  
pp. 988 ◽  
Author(s):  
Guang Li ◽  
Jianqing Li
Keyword(s):  
Wavelength Division Multiplexing ◽  
Optical Transmission ◽  
Signal To Noise Ratio ◽  
Optical Filter ◽  
Optical Signal ◽  
Transmission System ◽  
Signal To Noise ◽  
Dense Wavelength Division Multiplexing ◽  
Wavelength Division ◽  
Noise Ratio

In this paper, we propose an optical transmission system of 128 quadrature amplitude modulation for dense wavelength division multiplexing. In such a system, Gaussian optical filtering is used to get an appropriate photonic carrier. Theoretical analysis and simulation computation show that the modulated multi-carrier photonic signals with the wavelength spacing of 0.7 nm can transmit for over 80 km with the standard single mode fiber. Using digital signal processing algorithms to compensate the transmission impairments, the transmission rate of the single-carrier photonic signal can reach up to 904 Gbps and the spectral efficiency of the transmission can reach up to 10.33 bps/Hz. When this technology is applied to a dense wavelength division multiplexing system with N channels, the huge message capacity of N × 904 Gbps can be realized. Furthermore, we find that the bit error rate and the error vector magnitude are similarly influenced by the optical signal-to-noise ratio and the bandwidth of the Gaussian optical filter. The influence presents mostly a synchronization trend with the change of the optical signal-to-noise ratio and the bandwidth of Gaussian optical filter.

8CH AWG Multi/Demultiplexer With MEMS Variable Optical Attenuator

2003 ◽  
Author(s):  
K. Ishikawa ◽  
Q. Yu
Keyword(s):  
Wavelength Division Multiplexing ◽  
Optical Signal ◽  
Arrayed Waveguide Grating ◽  
Optical Contrast ◽  
Network Systems ◽  
Micro Electro Mechanical Systems ◽  
Wavelength Division ◽  
Power Intensity ◽  
Variable Optical Attenuator ◽  
Arrayed Waveguide

An integrated arrayed waveguide grating multi/demultiplexer (AWG) with a micro-electro-mechanical systems (MEMS) based variable optical attenuator (VOA) is reported. The device consists of an AWG based on silica and a MEMS-VOA chip. The MEMS chip includes 100 μm × 100 μm polysilicon shutter plates coated with gold and electrostatic comb-drive actuators. The MEMS chip is interposed in a trench located in the middle of the I/O waveguides of the AWG to tune the optical transmitting power intensity through the waveguides continuously. The MEMS-VOA shutters have more than a 10 μm displacement. Using those shutters, 30 dB optical contrast from 5 dB at the transmit state to 35 dB at the isolation state is achieved. The obtained attenuation contrast is greater than that of a conventional waveguide-based Mach-Zehnder interferometer VOA and sufficient to adjust and equalize the optical signal power in the wavelength division multiplexing (WDM) network systems.

Investigation and optimization of EYDFA + Raman + EYDFA hybrid optical amplifier for SD-WDM systems in C+L band

2021 ◽  
pp. 2150006
Author(s):  
Anurupa Lubana ◽  
Sanmukh Kaur
Keyword(s):  
Wavelength Division Multiplexing ◽  
Signal To Noise Ratio ◽  
Fiber Amplifier ◽  
Optical Amplifier ◽  
Optical Signal ◽  
Channel Spacing ◽  
Channel System ◽  
Wavelength Division ◽  
Gain Variation ◽  
Hybrid Optical Amplifier

In this paper, we present a novel erbium–ytterbium doped fiber amplifier (EYDFA) + Raman + EYDFA hybrid optical amplifier (HOA) for a super-dense wavelength division multiplexing (SD-WDM) system application. The performance of the 100-channel system has been investigated for an overall data rate and channel spacing of 100[Formula: see text]Gb/s and 0.4[Formula: see text]nm, respectively, over a wavelength span of 1550–1589.9[Formula: see text]nm. HOA has been optimized for Raman length, EYDFA lengths, pump powers and Er[Formula: see text] concentrations to achieve high average gain and low gain variation ratio of 40.41[Formula: see text]dB and 0.40[Formula: see text]respectively. The optimized configuration of the proposed HOA has been compared with EYDFA + Raman and Raman + EYDFA HOA configurations. The achieved high and flat gain with an acceptable output optical signal to noise ratio (OSNR) in case of EYDFA + Raman + EYDFA HOA; makes it an optimum choice for SD-WDM systems.

scholarly journals Thermo-Optic Tunable Optical Filter Based on Fabry-Perot Microcavities in SOI

2012 ◽  
Vol 6-7 ◽  
pp. 194-199
Author(s):  
Zhe Li ◽  
Hua Juan Qi ◽  
Yong Chuan Xiao ◽  
Feng Li Gao
Keyword(s):  
Refractive Index ◽  
Wavelength Division Multiplexing ◽  
Optical Filter ◽  
Silicon On Insulator ◽  
Central Wavelength ◽  
Wavelength Division ◽  
Tunable Optical Filter ◽  
Compact Size ◽  
Fabry Perot ◽  
Output Characteristics

An integrated TOF (Tunable Optical Filter) based on thermo-optic effect in Silicon on insulator (SOI) rib waveguide is designed and simulated. The device is comprised of two high refractivity contrast Si/Air stacks, functioning as high reflectivity of DBRs and separated by a variable refractive index Si F-P cavity. The output characteristics are calculated and simulated based on Transfer Matrix Method (TMM). Wavelength tuning is achieved through thermal modulation of refractive variation of the cavity.As the cavity Si is heated,the refractive index of the cavity increases.When the temperature of cavity Si changes within100°C，the central wavelength gets a continuous 8nm shift from 1550nm to 1558nm, which is right located in the WDM (Wavelength division multiplexing) networks operating at C-band. Moreover, by calculating, the tuning sensitivity is about 0.08nm/°C. Owing to the compact size and excellent characteristics of integration, the proposed component has a promising utilization in spectroscopy and optical communication.

Effect of Crosstalk in Super Dense Wavelength Division Multiplexing System using Hybrid Optical Amplifier

2019 ◽  
Vol 40 (4) ◽  
pp. 347-351
Author(s):  
Chakresh Kumar ◽  
Rakesh Goyal
Keyword(s):  
Wavelength Division Multiplexing ◽  
Optical Communication ◽  
Power Level ◽  
Optical Amplifier ◽  
Optical Signal ◽  
Dense Wavelength Division Multiplexing ◽  
Channel Spacing ◽  
Wavelength Division ◽  
Fiber Nonlinearity ◽  
Hybrid Optical Amplifier

Abstract Analysis of proposed 400×10 Gbps super dense wavelength division multiplexing (SD-WDM) system has been evaluated in term of crosstalk and optical signal to crosstalk ratio (OSCR). Amplification is carried out using RAMAN-EDFA hybrid optical amplifier (HOA) for the transmission of 300 km. The pump power of 550 mW at 1520 nm and 580 mW at 1530 nm are set to RAMAN and EDFA optical amplifier respectively. Further, the power level of 0 dBm with channel spacing of 100 GHz has shown the remarkable outcome of controlling the fiber nonlinearity to maintain the best rating optical communication for long haul distance.

scholarly journals Absolute polar duty cycle division multiplexing over wavelength division multiplexing system

2009 ◽  
Vol 282 (21) ◽  
pp. 4233-4241 ◽  
Author(s):  
Amin Malekmohammadi ◽  
Ahmad Fauzi Abas ◽  
Mohamad Khazani Abdullah ◽  
Ghafour Amouzad Mahdiraji ◽  
Makhfudzah Mokhtar ◽  
...  
Keyword(s):  
Wavelength Division Multiplexing ◽  
Duty Cycle ◽  
Wavelength Division

scholarly journals Transmission (2Gbps) over optical fiber cable by using radio over fiber and wavelength division multiplexing techniques

2019 ◽  
Vol 24 (5) ◽  
pp. 115
Author(s):  
Humam Husseinˡ ◽  
Dogu Cagdas Atilla1 ◽  
Essa Essa2 ◽  
Cagatay Aydin1
Keyword(s):  
Optical Fiber ◽  
Wavelength Division Multiplexing ◽  
Performance Test ◽  
Optical Signal ◽  
Radio Over Fiber ◽  
Total Power ◽  
Q Factor ◽  
Wavelength Division ◽  
Fiber Technology ◽  
Optical Fiber Cable

In recent years, there has been a growing and continuous demand for great (data rates) beyond existing wired and wireless networks. Radio-over-Fiber technology is considered as an efficient and practical solution for providing broadband wireless. In this paper, many techniques are used to implement a system that has the capability to provide a great bit rate, broadband bandwidth, and minimum cost. So Radio-over-Fiber technology was used to modulate the light with radio-signal and transmission the signals through an optical fiber cable. Wavelength-Division-Multiplexing technique was used to send many signals through the same link, and Subcarrier Multiplexing-Amplitude Shift keying as a modulation format. 2Gpbs separate on two channels was transmitted on Single-Mode Fiber. The average results obtained from our experience was as follows: maximum Q factor average = 4.9712925, minimum BER average = 3.63*10-7, total power average (dBm) = -51.1502, the OSNR average (dB) = 52.085 for channel_1. The results of channel_2 were: maximum Q factor average = 5.5901325, minimum BER average = 1.26*10-8, total power average (dBm) = -46.60135, the average of optical signal-to-noise ratio (dB) = 54.65. All the average result that has from our simulation was very good and acceptable. The simulation and performance test of our experience was done using Optisystem 7.0.   http://dx.doi.org/10.25130/tjps.24.2019.100

Investigation on Ultra-compact 2DPC Coarse Wavelength Division Demultiplexer

2021 ◽  
Author(s):  
Venkatachalam Kannaiyan ◽  
Sriram Kumar D ◽  
Robinson S
Keyword(s):  
Integrated Circuits ◽  
Wavelength Division Multiplexing ◽  
Photonic Band Gap ◽  
Fdtd Method ◽  
Spectral Width ◽  
Transmission Efficiency ◽  
Circular Ring ◽  
Channel Spacing ◽  
Wavelength Division ◽  
Functional Parameters

Abstract A two dimensional Photonic Crystal (2DPC) based eight channel wavelength division demultiplexer is proposed and designed for Coarse Wavelength Division Multiplexing (CWDM) applications. The circular ring resonator, channel selector, circulator rod, L bend waveguide and linear bus waveguide are essential parts of the proposed system. The system’s functional parameters such as Transmission efficiency, resonant wavelength, spectral width, channel spacing, Quality factor and crosstalk are investigated in this paper. The eight different wavelengths of channels are filtered out by altering the size of channel selector rod, setting the radius of the circle shaped cavity and relative refractive index of circulator rod. Initially the Photonic Band gap (PBG) is manipulated by applying Plane Wave Expansion (PWE) method of the 2DPC structure. The functional parameters are analysed by Finite Difference Time Domain (FDTD) method in periodic and non-periodic structure of the proposed system to arrive normalized transmission spectrum. The resonant wavelengths of designed eight paths of the device are varying from 1420nm to 1460nm with average spectral width and channel spacing are 5.8nm, 5.6nm respectively. The footprint of the device is 286.84µm2. Hence this small device can be implemented for CWDM systems in Photonic Integrated Circuits (PIC).

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