Dense Wavelength-division-multiplexing Passive Optical Network Research Articles

Application of FWM-Based OFC for DWDM Optical Communication System with Embedded FBG Sensor Network

Abstract Four-wave mixing optical frequency comb fibre-based setups (FWM-OFCs) have the potential to improve the combined dense wavelength division multiplexed passive optical network (DWDM-PON) and fibre Bragg grating (FBG) temperature sensors network providing easier application, broader technological opportunities for network development, and energy efficiency by substituting a power-demanding laser array. In this research, OFCs are generated for the purpose of combined network application of DWDM-PON and FBG optical sensors. The paper also investigates compatibility scenarios with OFCs in such systems. The mathematical simulation model has been developed and the performance of FWM-OFC based 8-channel 50 GHz spaced non-return-to-zero on-off keying (NRZ-OOK) modulated DWDM-PON transmission system, operating at 50 km single-mode fibre (SMF) with a bit rate of at least 10 Gbps embedded with 7 FBG optical temperature sensors, has been studied. As it is shown, FWM application results in OFC source that has fluctuations of the individual comb tones of less than 3 dB in power, and with an extinction ratio of about 33 dB for operation range of 192.9–193.25 THz, acting as a unified light source for all the data transmission channels. Embedded FBG optical sensors network causes negligible 0.3 dB power penalty.

Design and Performance Analysis of DWDM-PON

This paper presents on the design and analysis of Dense Wavelength Division Multiplexing Passive Optical Network (DWDM-PON) which is the upcoming trend technology nowadays to transmit up to 40 Gbps data. Various modulation techniques such as Non-Return Zero (NRZ), Return-Zero (RZ) and duo binary coding are simulated in this DWDM-PON. Using OptiSystem software, DWDM-PON is designed and simulated for 32 channels with spacing of 100 GHz and bit rate of 10 Gbps. An Erbium Doped Fiber Amplifier (EDFA) and Dispersion - Compensating Fiber (DCF) is deployed in the DWDM design. It is found that duo binary modulation technique gives the best performance with minimum BER of 2.66x10-19. From the simulation result, it also found that the proposed DWDM PON design is suitable to be deployed for current network.

Wavelength-Tunable OTDR for DWDM-PON Based on Optimized Wavelet Denoising

In this letter, a wavelength-tunable Optical Time-Domain Reflectometer (OTDR) for Dense Wavelength Division Multiplexing Passive Optical Network (DWDM-PON) is proposed and experimentally demonstrated. An Integrated Tunable Laser Assembly (ITLA) serves as the light source permitting measurements of 80 DWDM channels in the C-band. Dither modulation is added to ITLA to depress coherent noise resulted from the narrow linewidth of the light source. Semiconductor Optical Amplifier (SOA) modulates the continuous light into pulsed light and meanwhile amplifies peak optical power of the pulsed light to 13 dBm. In addition, we optimize the wavelet denoising algorithm for further signal-noise ratio (SNR) enhancement. Dynamic range and spatial resolution of the proposed OTDR reach up to 16.2 dB and 2 m respectively. A DWDM-PON fiber link including an Arrayed Waveguide Grating (AWG) is measured to verify the system performances, and the OTDR profiles of different channels coincide with each other. The designed wavelength-tunable OTDR is shown to be appropriate for DWDM-PON.

Improving FWM efficiency in bi-directional ultra DWDM-PON networking centered light source by using PMD emulator

The optical networks provides a high performance data networking and secured way to communicate. New generation optical networks demands high input power and low channel spacing in Wavelength-Division Multiplexing (WDM). Using WDM can lead to some nonlinearities in the system such as Four Wave Mixing (FWM). FWM is a phenomena in which two optical pulses are converted into four pluses after traveling in optical fiber. In this paper Polarization Mode Dispersion (PMD) is used by applying PMD emulator at input to suppress FWM. To analyse the effect of PMD a Dense Wavelength-Division Multiplexing-passive optical network (DWDM-PON) is used with centerlized source over the transemission distance longer than 50 km. System’s performance is carried out on the basis of Q factor, optical signal to noise ratio (OSNR), bit error rate (BER), received power and FWM efficiency. Exhaustive sets of simulations are carried out in “Optisystem” on a eight channel system having 25 GHz spacing, operating at 5 Gbps. Results show 7 dB and 5 dB of improved FWM efficiency in downlink and uplink respectively.

Mode division multiplexing and dense WDM-PON for Fiber-to-the-Home

In this paper, a dense wavelength division multiplexing - passive optical network (DWDM-PON) architecture was designed using vertical cavity surface emitting laser (VCSEL) arrays for mode division multiplexing (MDM) of Laguerre-Gaussian (LG) modes LG12, LG15. LG18, LG111 and LG114. A data rate of 25Gbit/s has been achieved at a central wavelength 1550.12 nm with a spacing of 1.6 nm. Transmission performance was compared for multimode fiber (MMF) lengths of 200 m to 1 km. The modal performance has been evaluated using spatial electric field, electric signal, eye diagram and bit-error-rates (BER).

Two-color laser diode for 54-Gb/s fiber-wired and 16-Gb/s MMW wireless OFDM transmissions

A two-color, laser-diode-based, full-duplex fiber-wired and millimeter-wave (MMW)-wireless orthogonal frequency-division multiplexing (OFDM) transmission link is performed. With modal control on the two-color laser diode, a single-wavelength optical carrier is used as both the downstream and upstream transmitters to replace the dual-mode one with an optical baseband, which effectively suppresses the chromatic dispersion that occurs in fiber. The proposed system demonstrates a carrier-reused, full-duplex 28-GHz MMW dense wavelength division multiplexing passive optical network (DWDM-PON) system, providing OFDM transmission with 54 Gb/s downstream, 36 Gb/s upstream and 16 Gb/s wireless data rates. The single-wavelength optical carrier transmits data from an optical line terminal (OLT) to a remote node (RN) and then transfers into a dual-wavelength carrier for optically heterodyne beating an MMW carrier, which further wirelessly transmits the data to an optical network unit (OUN). In addition, the upstream data is carried by another slave colorless laser diode injection-locked by reusing the downstream carrier without additional data erasing, which avoids the wavelength selection problem that resulted from identifying or addressing upstream and downstream channels. Among three laser transmitters with different cavity lengths, the 600-μm embedded MMW wireless carrier can provide the lowest bit error rate (BER) after 25 km of fiber and 1.6-m free-space transmissions at 16 Gb/s, because its highest external quantum efficiency supports the optimization on self-heterodyne transferring the MMW carrier to enable the low-noise and long-distance wireless transmission.

Long reach DWDM-PON with 12.5 GHz channel spacing based on comb source seeding

A long reach dense wavelength division multiplexing passive optical network (DWDM-PON) with 12.5 GHz channel spacing is proposed and experimentally demonstrated. An optical frequency comb source is used to provide the multiwavelength seeding light, while reflective semiconductor optical amplifiers (RSOAs) are installed in both optical line terminal (OLT) and optical network units (ONUs) as colorless transmitter. The experimental results show that the bidirectional transmission for 1.2 Gbit/s data rate is achieved over 80 km single mode fiber (SMF).

Wavelength Resource Sharing in Bidirectional Optical Mobile Fronthaul

In this paper, we propose high-capacity spectrally-efficient optical mobile fronthaul (MFH) architectures featuring wavelength resource sharing, where multiple cell sites share one dense wavelength division multiplexing (DWDM) channel instead of occupying a number of separated DWDM channels. In the downlink (DL), subcarrier multiplexing (SCM) is integrated with DWDM passive optical network. The key technical innovation lies in the reception of uplink (UL) signals being optically aggregated with ultrasmall spacing. We introduce two novel schemes for spectrally-efficient and low-complexity upstream transmissions. The first method is based on SCM in remote radio heads (RRHs) and coherent detection in baseband units (BBUs), achieving channel spacing of as small as 100 MHz. For the first time, successful coherent reception of LTE signal, whose symbol rate (15 ksps) is much smaller than the laser linewidth, is achieved by pairing a radio frequency pilot tone from each RRH. Bidirectional transmission of four 20-MHz 16-QAM-OFDM LTE-like signals with 100-MHz spacing aggregated on one wavelength is demonstrated. For the second proposed UL scheme, we report a low-complexity ultradense WDM over DWDM allocation with 1-GHz wavelength spacing and novel phase-noise-insensitive heterodyne detection using MHz-linewidth lasers and an off-the-shelf envelope detector. We experimentally demonstrate the transmission and simple detection of multichannel 100/200 Mb/s OOK or 200 Mb/s 16-QAM-OFDM signals with 1-GHz spacing over 30-km standard single mode fiber using 5-MHz-linewidth lasers. By enabling ultrahigh spectral efficiency, high receiver sensitivity, and low-complexity, the proposed approach achieves a significant breakthrough for future high-capacity mobile fronthaul systems.

Bidirectional 10 Gb/s/λ, channel-reuse, long-reach DWDM-PON employing tunable optical transceiver with optical intensity detection-based wavelength management

We experimentally demonstrate a channel-reuse, bidirectional 10 Gb/s/λ, long-reach dense wavelength-division-multiplexing passive optical network (DWDM-PON) and an optical intensity detection-based wavelength management method for tunable optical transceiver used in colorless optical network unit. A channel-reuse, full-duplex, 42 km/87 km reach without/with optical amplification, 10 Gb/s transmission on a 50 GHz DWDM grid is achieved. Transmission performance is also measured with different optical-signal-to-Rayleigh-backscattering-noise ratios (OSRBNRs) and different central wavelength shifts between upstream signal and downstream signal in the channel-reuse system. Optimal operating wavelength for the uplink optical signal and effective OSRBNR configurations taking into account AWG pass-band, wavelength instability of the downlink optical transmitter and the distance of the feeder fiber are proposed.

Channel-reuse bidirectional transmission at 10 Gb/s/λ in long-reach DWDM-PON employing self wavelength managed tunable laser

We experimentally demonstrate a channel-reuse, bidirectional, 10Gb/s/λ, long-reach dense wavelength-division-multiplexing passive optical network (DWDM-PON) and an optical beat noise-based automatic wavelength control method for a tunable laser used in a colorless optical network unit (ONU). A 42km reach, channel-reuse, full-duplex, 10Gb/s transmission on a 50GHz DWDM grid is achieved. Transmission performance is also measured with different optical-signal-to-Rayleigh-backscattering-noise ratios (OSRBNRs) and different central wavelength shifts (WSs) between upstream signal and downstream signal in the channel-reuse system.

Fifty-five km reach, bidirectional, 400 Gb/s (40 \times 10 Gb/s), channel-reuse DWDM–PON employing a self-wavelength managed tunable laser

We experimentally demonstrate a channel-reuse bidirectional 10 Gb/s/λ long-reach dense wavelength-division multiplexing passive optical network (DWDM-PON) and an optical beat-noise-based automatic wavelength control method for a tunable laser used in a colorless optical network unit (where λ=wavelength). A 55 km, bidirectional, 400 Gb/s (40×10 Gb/s) capacity channel-reuse transmission with 100 GHz channel spacing is achieved. The transmission performance is also measured with different optical signal to Rayleigh backscattering noise ratios and different central wavelength shifts between upstream and downstream in the channel-reuse system.

25-GHz-Spaced DWDM-PON With Mitigated Rayleigh Backscattering and Back-Reflection Effects

A novel 25-GHz-spaced dense wavelength-division multiplexing passive optical network (DWDM-PON) is proposed to improve the utilization of wavelength resource and mitigate the Rayleigh backscattering (RB) and back-reflection effects. A colorless optical network unit (ONU) is realized by remodulating the downstream (DS) signal via a gain-saturated reflective semiconductor optical amplifier (RSOA). Due to the simple interconnecting architecture at the remote node (RN), the DS and upstream (US) signals in each feed fiber (FF) are carried on different channels. Therefore, the RB and back-reflection effects are significantly reduced. The feasibility and merits of the proposed system are experimentally demonstrated with the error-free transmission of 10-Gb/s DS and 1.25-Gb/s US signals over a 25-km single-mode fiber.

High-Capacity DWDM-PON Using Triple-Contact F-P LDs

We demonstrate a dense wavelength-division-multiplexing passive optical network (DWDM-PON) at 50-GHz channel spacing based on wavelength locked triple-contact Fabry-Perot laser diodes (TC F-P LDs). A transmission distance of 30 km was achieved at 1.25 Gb/s per channel. By controlling injected currents into three electrodes, we can match a lasing mode of the TC F-P LD to an injection wavelength. We also employ a prefilter before amplified spontaneous emission (ASE) injection to enhance the system performance by reducing a filtering effect. The transmission distance was limited by the back scattering. By changing a location of the seed source for upstream signal to the remote node, the transmission distance can be extended up to 60 km.

Demonstration of a Long-Reach DWDM-PON for Consolidation of Metro and Access Networks

We demonstrate a bidirectional long-reach 64-channel dense wavelength division multiplexing passive optical network (DWDM-PON) based on wavelength-locked Fabry-Peacuterot laser diodes (F-P LDs) with 50-GHz channel spacing. The mode control of the F-P LDs enhances the output power and decreases the required injection power. Packet-loss-free transmission in both 64 upstream and 64 downstream channels is obtained, guaranteeing more than 100 Mb/s per channel through 70 km of single mode fiber without the need for an optical amplifier. The demonstrated DWDM-PON can consolidate a metro network into an access network by bypassing the central offices within its reach. The capacity of the long-reach DWDM-PON is also discussed

Dense WDM-PON based on wavelength-locked Fabry-Pe/spl acute/rot laser diodes

We demonstrate a bidirectional 12-channel wavelength-division-multiplexing passive optical network (WDM-PON) with 50-GHz channel spacing based on wavelength-locked Fabry-Pe/spl acute/rot laser diodes. The maximum transmission length is 30 km including 20 km of feeder fiber and 10 km of distribution fiber. The proposed WDM-PON system can accommodate 80 channels with erbium-doped fiber amplifier-based broad-band light sources. We also propose a few methods for the wavelength-independent operation of an optical network termination.