Dispersion Compensation Research Papers - Academia.edu (original) (raw)

2025, Optical Fiber Communication Conference

We report full C-band tunable, 10 Gbit/s capability, directly modulated MEMS-VCSEL for next generation converged mobile fronthaul and backhaul applications. Bit error rates below 10 -9 were achieved over up to 40 km SSMF.

2025, 39th European Conference and Exhibition on Optical Communication (ECOC 2013)

We present a multi-channel transmitter that employs an arrayed reflective electroabsorption modulator-based photonic integrated circuit and low-power driver array. Error-free 11.3-Gb/s per channel performance is achieved over 96 km of... more

2025

We demonstrate nonlinear pulse compression by multi-pass cell spectral broadening (MPCSB) from 860 fs to 115 fs with compressed pulse energy of 7.5 µJ, average power of 300 W and close to diffraction-limited beam quality. The transmission of the compression unit is >90%. The results show that this recently introduced compression scheme for peak powers above the threshold for catastrophic self-focusing can be scaled to smaller pulse energies and can achieve a larger compression factor than previously reported. Good homogeneity of the spectral broadening across the beam profile is verified, which distinguishes MPCSB among other bulk compression schemes.

2025, Optics Express

2025, Chinese Optics Letters

Based on the coupled Ginzburg-Landu equation, we numerically investigate the pulse dynamics in a dispersion-managed normal dispersion Tm-doped mode-locked fiber laser. The influences of the modulation depth and saturation power of saturable absorber on the pulse dynamics are presented. The simulation results show that these parameters are crucial to achieve high pulse energy and high pulse peak power pulsed laser near 2-µm wavelength.

2025, IEEE Journal of Selected Topics in Quantum Electronics

In this paper, we demonstrate experimental alloptical code-division multiplexing (AO-CDM) systems using 64-ps optical pulses and a 2 n prime code of n = 3. A distinguishing feature of this experiment is that the modulation of ultrashort optical clock stream by electrical data is realized without using any optical intensity modulator at each transmitter. Moreover, only low-cost standard optical 2 2 2 couplers and fiber delay lines are employed to implement all-serial encoders and decoders for a 2 n prime code. As a result, this new system is more cost-and power-effective than a conventional AO-CDM system. Furthermore, the use of AO-CDM systems can offer parallel communications over a common fiber channel, which in turn can support real-time computer interconnections for image and data communications.

2025, Journal of Lightwave Technology

We investigate 40-Gb/s cost-efficient transmitter for access and metro networks. This 40-Gb/s transmitter comprises a standard directly modulated distributed-feedback (DFB) laser and a subsequent optical filter. Large dispersion tolerance of this transmitter is realized by chirp control through the phase correlation between adjacent bits for the destructive interference in order to erase the power of "0" bits while enhancing the extinction ratio. The chirp model of the DFB laser and the optimum parameters of the optical filter have been numerically analyzed. The chirp-managed 42.8-Gb/s transmission over 20-km standard single mode fiber (SSMF or SMF-28) without dispersion compensation and a centralized lightwave WDM-PON system are experimentally demonstrated. We have also realized the transmission over 100-m graded index plastic optical fiber (GI-POF). Moreover, the application in the metro network over 240-km SSMF or SMF-28 has also been investigated in this paper.

2025, IEEE/CAA Journal of Automatica Sinica

Technique for selective localization of four-photon mixing and its use for physical parameter extraction in fiber is described. The measurement method relies on localized countercolliding power transfer and was applied to map dispersion and corresponding transverse geometry of different types of optical fibers. The technique is capable of resolving fiber core fluctuations comparable to a single silica molecular diameter.

2025, IEEE Photonics Technology Letters

2025, IEEE Transactions on Communications

We evaluate the theoretical performance of recently proposed optical coding (OC) technology for fiber fault monitoring of a PON through the signal-to-noise ratio (SNR), the signal-to-noise-plus-interference ratio (SNIR), and the falsealarm probability. First, we develop a mathematical model and expressions for the detected monitoring signals considering a square law detector and using realistic parameters. Second, we address the effect of the transmitted pulse power, network size and light source coherence on the performance of both one-dimensional (1D) and two-dimensional (2D) OC monitoring systems. We show that the transmitted pulse width can be optimized to trade-off the interference and the detection noises. We give simple analytic equations for this optimal pulse width as a function of network parameters. Both 1D and 2D coding schemes are considered. We find that, under perfect dispersion compensation, an incoherent source performs better than lasers for 1D coding. In addition, 2D coding using lasers offer very good performance and supports networks up to 128 customers with SNIR≥10dB; a promising candidate for future high capacity PON. Finally, we apply Neyman-Pearson testing to the receiver of our monitoring system and investigate how coding and network size affect the operational expenses (OPEX) of our monitoring system.

2025

An optical architecture is described that offers the maximum interconnectivity afforded by light. The switch is described conceptually, and specific implementations are detailed for a prototype and for a large-scale version that supports more than 10 million channels, each of which carries data at rates of 10 Gbit/s or more. Results for a prototype are presented. Implementation issues, including off-axis propagation and filter angular sensitivity, are addressed. The architecture supports a new generation of parallel routers, and the switch is strictly nonblocking if color switching is not required. Modest levels of color switching, i.e., wavelength changing, can be supported by the architecture with little change by use of an optical foreplane. If full color switching is required, an optical backplane compatible with the architecture is used. Both opaque (optical-electronic-optical) and transparent (mirror array) versions of the switch are described. The architecture can support very low-cost switches for two reasons: (1) The underlying components can utilize wafer-based technologies, and (2) a single alignment can align hundreds or even thousands of channels at once.

2025, Automatika : časopis za automatiku, mjerenje, elektroniku, računarstvo i komunikacije

In this paper the Asymmetric Digital Subscriber Line (ADSL) analog front end (AFE) designs are described and compared. AFE is the part of ADSL modems most responsible for quality signal transmission over phone wires. It can be divided into the transmitting path (TX) circuitry, the receiving path (RX) circuitry and the hybrid network and transformer. The operations and realizations of each functional block are presented. There are the D/A converter, the filter and the line driver in the TX path and the voltage gain amplifier, the filter and the A/D converter in the RX path. The hybrid network and transformer process signals in both directions. Different fabrication technologies are used for the practical realizations of the AFE chip. The directions of the further developing are notified.

2025, SPIE Proceedings

The phase response of a commercial saturable absorber based on semiconductor quantum wells embedded in a resonant cavity is investigated. The nonlinear absorption change is accompanied by a variation of the spectral phase characteristic. Also, a nonlinear change in the refractive index of the material, induced by the modified carrier density, produces a weak shift in the resonant wavelength of the cavity. These effects can be exploited to realize an optically-controllable phase shifter. Simulations based on a nonlinear model are also carried out in order to investigate the effect of the various cavity parameters and phase response of the device under different operating conditions. The results from this characterization and numerical analysis show that such device can have the potential for practical applications in telecom systems, including dynamic dispersion compensation, tunable nonlinear effects compensation, and nonlinear signal processing and all-optical regeneration of phase-modulated optical signals.

2025, IEEE Photonics Journal

We propose and experimentally demonstrate that, contrary to what was thought up to now, an efficient BB84 operation is feasible using the double phase modulator (PM-PM) configuration in frequency-coded quantum key distribution systems without dispersion compensation. This is achieved by exploiting the chromatic dispersion provided by the fiber linking Alice and Bob. Thus, we refer to this system as dispersion supported or as the DS BB84 PM-PM configuration.

2025, EA Otsapa

In wireless communication systems, it is frequently preferable to use a null steering beamformer to reduce interference from strong narrowband signals and other multipath signals. This paper proposes an efficient narrowband null-steering beamformer based on an Improved Davies Narrowband Null-steering (IDNN) algorithm combined with an Improved Constant Modulus Algorithm (ICMA). The designed beamformer can impose adaptive nulls at interferences without knowing directions in the side lobe region by employing the ICMA for signal adaptation,while maintaining the main lobe toward the desired user direction. The results reveal that the developed beamformer increased the convergence rate by 12.8%, as seen by lower output power convergence when compared to the traditional Davies Narrowband Null-steering (DNN) algorithm. Thus, the new algorithm is observed to have much faster convergence behavior.

2025, IEEE Photonics Technology Letters

In this letter, we have developed a tandem electroabsorption modulator with an integrated semiconductor optical amplifier that is capable of both nonreturn-to-zero and return-to-zero (RZ) data transmission at 40 Gb/s. The tandem modulator consists of a broad-band data encoder and a narrow-band pulse carver. The pulse carver is able to produce 5-ps pulses with more than 20 dB of extinction. The on-chip semiconductor optical amplifier provides up to 8.5 dB of fiber-to-fiber gain and enables the modulator to be operated with zero insertion loss. Devices have been realized with greater than 40-GHz bandwidth, and 13-dB dynamic extinction for a 2.5-V swing. For optimized designs bandwidths of nearly 60 GHz have been realized. Using these devices penalty free RZ data transmission over a 100-km dispersion compensated fiber link has been demonstrated with a received power sensitivity of 29 dBm.

2025

In this paper we present results of the research aimed at designing and manufacturing a prototype of a SHM system that employs Phased Arrays (PA) for generating and receiving Lamb Waves (LW). A linear array was considered first but it appeared that an unequivocal localization of damage on a plane panel requires a 2D array's topology. In this paper we present a new method for theoretical, numerical and experimental investigations of various 2D arrays' topologies for SHM of planar structures. The theoretical evaluation is performed using the frequency-dependent transfer function that affects propagation of Lamb waves (LWs) through the dispersive medium and enables investigation of the arrays' performance for a defined excitation signal. The numerical simulations are conducted using local interaction simulation approach (LISA) implemented on the NVIDIA® CUDA® graphical processing unit (GPU), which considerably accelerates 3D simulations of LWs propagation in a short time period. Finally, scanning laser vibrometer is used to sense the LWs excited by PZT transducers, in multiple points corresponding to the locations of the 2D array elements. In this way performance of various array topologies can be evaluated experimentally in the reception mode without the need of physical prototype -a change of topology requires only straightforward modification of the measurement points' distribution at the tested plate.

2025

Achievement of transmission (full duplex) over single fiber is a challenge for researchers for Wavelength Division Multiplexed Passive Optical Networks. There are many schemes available but they suffer from transmission issues because of using transmissions on the same wavelength with bidirectional transmissions. This results in the reduction of transmission distances between optical fiber terminal equipment and the optical network units. This happens because Rayleigh’ backscattering noise and there is a need to reduce that noise substantially. In this research work channels capacity Dense Wavelength Division Multiplexing (DWDM), Passive Optical Networks (PON) are simulated after extensive testing. The main aim is enhancing the capacity over a distance with less bit error rates. This was achieved through the design optimization using Rayleigh’ Backscattering elimination technique thus enhancing the performance.

2025, Photonic Materials, Devices, and Applications II

2025, HAL (Le Centre pour la Communication Scientifique Directe)

In this presentation we would discuss design and fabrication issues with regard to dispersion tailoring of optical fibers for specialty applications. Various design tools, which could be exploited for such purpose, would be discussed.

2025

I, Janelle Claire Shane, hereby certify that this thesis, which is approximately 24,000 words in length, has been written by me, that it is the record of work carried out by me and that it has not been submitted in any previous application for a higher degree. Date 9.5.09 Signature of Candidate I was admitted as a research student in August 2007 and as a candidate for the degree of Master of Philosophy in August 2007; the higher study for which this is a record was carried out in the University of St Andrews between 2007 and 2008. Date 9.5.09 Signature of Candidate I hereby certify that the candidate has fulfilled the conditions of the Resolution and Regulations appropriate for the degree of Master of Philosophy in the University of St Andrews and that the candidate is qualified to submit this thesis in application for that degree. Date 19.5.09 Signature of Supervisor In submitting this thesis to the University of St Andrews we understand that we are giving permission for it to be made available for use in accordance with the regulations of the University Library for the time being in force, subject to any copyright vested in the work not being affected thereby. We also understand that the title and the abstract will be published, and that a copy of the work may be made and supplied to any bona fide library or research worker, that my thesis will be electronically accessible for personal or research use unless exempt by award of an embargo as requested below, and that the library has the right to migrate my thesis into new electronic forms as required to ensure continued access to the thesis. We have obtained any third-party copyright permissions that may be required in order to allow such access and migration, or have requested the appropriate embargo below. The following is an agreed request by candidate and supervisor regarding the electronic publication of this thesis: Access to Printed copy and electronic publication of thesis through the University of St Andrews.

2025

Given the great impact of fiber Bragg gratings in DWDM communication networks we present a MatLab based graphical interface to design and model the FBG parameters to compensate the optical fiber link chromatic dispersion. This tool allows the spectral analysis of Apodized and Linearly Chirped FBG's in general as well as the design of the grating device that can compensate for the chromatic dispersion of an specified fiber link. The spectral characteristics of the designed grating are shown as well as an estimation of the deviation from the ideal theoretical compensator. The application is really cost-effective from the computational point of view and finally, it can also be displayed the time domain original pulse to be transmitted, the dispersion broadened pulse and the recompressed one as well as the compression ratio, to check the behavior of the designed system.

2025

The optimization of apodized linearly chirped fiber Bragg gratings in the field of chromatic dispersion compensation is discussed in terms of group delay response and pulse recompression. To develop this study two prototype scenarios are considered to show the different behavior of the compensating devices in function of the link length. Simulation results for 20 ps gaussian pulses transmitted and recompressed with different grating designs over the both links are presented. The maximum deviation error and the regression slope parameters are introduced to compare the quality of the group delay response to establish an optimum design of the apodization strength.

2025, IEE Proceedings - Optoelectronics

The impact of the apodisation sharpness on the spectral response of linearly chirped dispersion compensating gratings is evaluated. It will be demonstrated that the behaviour of the mean dispersion, group delay ripple, reflection bandwidth and insertion losses shows stronger dependence on the apodisation sharpness than on the type of apodisation profile. A detailed analysis is carried out with the view to compare the spectral characteristics of linearly chirped gratings applying different apodisation profiles with increasing sharpness to compensate the dispersion of 100 km of standard single-mode fibre. It will be shown that an apodisation factor of $ 0:8 results in minimum group delay ripple impact, minimum deviation from the required dispersion value and maximum reflection bandwidth ensuring, at the same time, minor increase of grating length and insertion losses compared with the non-apodised case. This value can be considered as the optimum apodisation sharpness for the profiles under study, allowing faster modelling and more effective fabrication steps for reflective dispersion compensating gratings.

2025, Optical and Quantum Electronics

We present an optimization process for the apodization strength factor of fiber Bragg grating dispersion compensators. It will be demonstrated that a proper choice of the apodization strength factor results in minimum deviation of the dispersion from the required level, maximum reflection bandwidth and minimum group delay ripple impact, thus leading to a reduction of the Q-factor penalty of the dispersion compensating system. We also discuss the influence of the fiber link length in the determination of the optimum apodization strength factor, taking into account that shorter links minimize the group delay ripple amplitude, whereas the longer ones maximize the bandwidth of interest. It is determined that a fiber link length of $80 km can balance the requirements of group delay ripple impact and bandwidth. The results obtained through this analysis allow a faster modeling of the Bragg grating parameters in order to achieve an improved spectral performance, as well as a cost-effective fabrication process.

2025

Implementing a dense wavelength division multiplexing (DWDM) configuration can substantially enhance the capacity of an optical communication system. Nonetheless, the DWDM system encounters notable challenges due to nonlinear effects that hinder its performance. Self-phase modulation (SPM), cross-phase modulation (XPM), and four-wave mixing (FWM) are three key factors that exert a significant influence on the system's optical communication capabilities. The primary objective of this research is to tackle and alleviate the nonlinear impact of cross-phase modulation within the DWDM system through an effective approach. In this research, we introduce a method for correcting dispersion in DWDM systems. These nonlinearities, encompassing self-phase modulation, cross-phase modulation, and four-wave mixing, are common occurrences in such systems. The researcher's proposal primarily centers on addressing cross-phase modulation. To comprehensively assess the DWDM system, we explored the effects of fluctuations in power and data rates. According to the results, a 32 channel DWDM system can effectively correct nonlinearities utilizing the suggested Symmetrical-Symmetrical-Post compensation technique (SSP) up to a transmission distance of 400 km using an input power of 20mW & data rate of 100 Gbps. These characteristics are ideal for long-distance optical communication. Suitably modifying the data rate and input power, it is feasible to increase no of channels and transmission distance. The new SSP method was also found to perform better than the conventional post-compensation methodology, making it more appropriate for long-haul DWDM systems. It is crucial to understand that the SSP technique by itself is unable to fully offset the spectral broadening brought on by cross-phase modulation. In order to solve this problem, combining sophisticated modulation methods with SSP can successfully reduce the spectrum broadening. This strategy can call for the use of more amplifiers, which could result in increased power consumption. In such configurations, dynamic control of the erbium-doped fiber amplifier (EDFA) is essential.

2025, Optik - International Journal for Light and Electron Optics

Simulations for data formats Return to Zero (RZ), Non-Return to Zero (NRZ), RZ-Soliton, Duobinary and their subcategories have been done with and without ideal dispersion compensation for optical communication systems. The results show that, in general, dispersion compensation improves timing jitter. RZ-Rectangular pulses show the smallest value of jitter without compensation. It has been observed that the RZ-Raised Cosine, and Soliton, give minimum jitter after ideal compensation. It has been reported that the BER performance of optical communication system using Duobinary data format is 10 À8 and 10 À37 before and after dispersion compensation, respectively. Further the comparative study shows that the timing jitter is the lowest in case of RZ-Soliton (0.0127 ns) after dispersion compensation and 0.0135 ns for RZ-Rectangular data format before dispersion compensation.

2025, IEEE Photonics Technology Letters

We have proposed a dispersion compensation scheme that uses a high-resolution arrayed-waveguide grating (AWG). When the diffraction order of the AWG is 59 and the number of waveguides in an arrayed-waveguide is 340, the calculated maximum second-and third-order dispersion compensation range is 68.0 ps/nm and 66.0 ps/nm 2 , and 6100 ps/nm and 6937.5 ps/nm 2 , for a 1 ps-pulse and a 12.5 ps-pulse, respectively. In experiments, second-order dispersion (00.8 to +5.2 ps/nm) is effectively compensated for 1.1-ps pulses; and pulse compression by third-order dispersion compensation is successfully demonstrated.

2025, Optics Letters

Periodic-group-delay (PGD) dispersion-compensation modules were recently proposed as mechanisms to alleviate collision-induced timing shifts in dispersion-managed (DM) systems. Frequency and timing shifts in quasi-linear DM systems with PGDs were obtained, and it is shown that significant reductions are achieved when even a small fraction of the total dispersion is compensated for by PGDs.

2025

Is standard single-mode fiber the fiber to fulfill the

2025, IEEE Photonics Technology Letters

The spectral characteristics of cross-phase modulation (XPM) in multispan intensity-modulation direct-detection optical systems were investigated both experimentally and theoretically. XPM crosstalk levels and its spectral features were found to be strongly dependent on fiber dispersion and optical signal channel spacing. Interference between XPM-induced crosstalk effects created in different amplified fiber spans is also found to be important to determine the overall frequency response of XPM crosstalk effects.

2024, Journal of Nondestructive Evaluation, Diagnostics and Prognostics of Engineering Systems

An important advantage of guided waves is their ability to propagate large distances and yield more information about flaws than bulk waves. Unfortunately, the multi-modal, dispersive nature of guided waves makes them difficult to use for locating flaws. In this work, we present a method and experimental data for removing the deleterious effects of multi-mode dispersion allowing for source localization at frequencies comparable to those of bulk waves. Time domain signals are obtained using a novel 64-element phased array and processed to extract wave number and frequency spectra. By an application of Auld’s electro-mechanical reciprocity relation, mode contributions are extracted approximately using a variational method. Once mode contributions have been obtained, the dispersion for each mode is removed via back-propagation techniques. Excepting the presence of a small artifact at high frequency-thicknesses, experimental data successfully demonstrate the robustness and viability of ...

2024, Optik - International Journal for Light and Electron Optics

We show the effect of varied order and width of super Gaussian pulse at 10 Gb/s in dispersion compensated optical communication system. The optical communication system consists of standard single-mode fiber of 16 ps/nm/km of a certain length, whose dispersion is compensated using pre-, post-and symmetrical-dispersion compensation schemes with proportionate length dispersion compensating fiber of À80 ps/nm/km. Performance of these three compensation schemes is compared at 14 dBm values of Er-doped fiber amplifiers (EDFA) power at 1st, 2nd and 3rd order RZ super Gaussian optical pulse. The pulse width, full width at half maximum (FWHM) is also varied from 5 to 30 ps to highlight the optimum performance. The graphical results obtained show a relationship among the attributes pulse width, order of RZ super Gaussian optical pulse and dispersion compensation scheme implemented. It shows that to decrease BER and timing jitter in the system, smaller width and 3rd order super Gaussian pulse should be used. It is recommended that to decrease dependency of BER and timing jitter in the communication system on the pulse width i.e. FWHM, the symmetrical compensation scheme should be implemented.

2024, Optik

We investigate the chirp selection of externally modulated RZ soliton pulse at 10 Gb/s for fiber optical communication systems for the reduction in timing jitter. We have chosen single arm Mach-Zehnder amplitude modulator with sin 2 electrical shaped input-output (P-V) characteristic and its chirp range has been varied in the range of À5 to 5. The timing jitter, Q factor and bit error rate (BER) generated for the chirp range has been studied for various fiber lengths and post compensation has been demonstrated to reduce the timing jitter. The number of fixed output amplifiers after every 60 km span is varied from 2 to 10 and corresponding accumulated ASE noise has been studied to manage timing jitter and BER in permissible range, i.e. 5 ps and 10 À9 , respectively. It is observed that when two fiber spans are taken then the compensating fiber length for the system is less than 20 km for each case of the chirp considered. For 10 fiber spans, the compensating fiber length increases in the range 60-90 km depending upon the value of chirp taken. Finally it is shown that the chirp value of external modulator should be set to either 0 or À1 for externally modulated RZ soliton pulse in 10 Gb/s optical communication system which makes the system more insensitive to the timing jitter and the selection of dispersion compensating fiber length.

2024, Optik

We have investigated the return-to-zero (RZ) pulse duty cycle for single-channel Standard Single mode fiber (SSMF), Non Zero Dispersion shifted fibers (normal NZDSF and anomalous NZDSF fiber) for 10 Gbps optical fiber communication system. We give a comprehensive look on the behavior of variable duty cycle optical RZ pulse indicating that lowest bit error rate for duty cycle 0.8 among the duty cycle values 0.2, 0.4, 0.6 and 0.8 investigated for the case of SSMF. The single repeaterless mode fiber length is increased from existing 55 km at duty cycle 0.2 to fiber length 85 km by keeping duty cycle at 0.8. The result is also emphasized through the 10 dB Q value improvement and corresponding improvement in average eye opening diagram. The normal NZDSF show similar improvement but at greater fiber length, it offers BER 10 À9 at length 110 km with duty cycle 0.2. NZDSF operating length can further be increased to length 160 km by keeping duty cycle 0.8. The corresponding 8 dB Q value improvement and Average eye opening improvement also supports the result through its graphical variation. Thirdly Anomalous NZDSF for same optical communication system showed that 0.2 duty cycle value give operational length of 130 km which could be extended to 160 km if 0.8 duty cycle is kept. The corresponding 8 dB Q value improvement, average eye-opening improvement endorsed the fact in the graphs.

2024, Optik - International Journal for Light and Electron Optics

2024, Electronics Letters

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2024, Optics Communications

We theoretically analyze the Gordon-Haus timing jitter in an optical transmission system with dispersion compensation. The enhanced power obtained in such a system reduces the frequency shift induced by noise, and choosing an appropriate position of the receiver further reduces the timing jitter converted from the frequency shift. Based on these results, we can obtain the reduction of the Gordon-Haus timing jitter in a dispersion compensated system, compared with a conventional soliton having equal pulse width and path-average dispersion. q 1998 Elsevier Science B.V.

2024, Optik - International Journal for Light and Electron Optics

We present results for duty cycle selection of optical RZ pulse to optimize the performance in 10 Gbps single channel dispersion compensated optical communication system. The system has link length of 240 km with two spans. Each of the spans consists of 120 km standard single mode fiber (SSMF) of 16 ps/nm/km, whose chromatic dispersion is compensated using pre-, post-and symmetrical-dispersion compensation schemes by 24 km dispersion compensating fiber (DCF) of À80 ps/nm/km. The performance of the three compensation schemes is compared by taking 8, 10, 12 and 14 dBm Er-doped fiber amplifier (EDFA) power levels in the link with a duty cycle range (0.1-0.9) of RZ optical pulse. The graphical results obtained show a relationship among the duty cycle, EDFA power and dispersion compensation scheme which predicts the best performing duty cycle case. To optimize performance of the system, we recommend in general, duty cycle less than 0.3 and EDFA power below 8 dB irrespective of compensation scheme. However, with post compensation duty cycle less than 0.7 and EDFA power below 12 dBm give optimum performance. The results conclude that for the high value of duty cycle, post dispersion compensation scheme should be used.

2024, Optik

2024, Optik - International Journal for Light and Electron Optics

2024

In Wavelength-division multiplexing (WDM) we are combining multiple signals at various infrared (IR) wavelengths on laser beams for transmitting the signal along fiber optic media. Generally there are two WDM techniques one is CWDM and another one is DWDM. Coarse wavelength division multiplexing (CWDM) is a method which will combine multiple signals on laser beams at various wavelengths for transmission along fiber optic cables, such that the number of channels is less as compared with dense wavelength division multiplexing (DWDM). In metro and cable TV network CWDM is getting more attention because with low cost it can transmit more bandwidth. In optical fiber communication system dispersion compensation is one of the most important feature because here the absence dispersion causes pulse spreading which results in overlapping of the signal in the receiver side. So, in order to compensate the dispersion here EDFA(Erbium doped fiber amplifier) is used. Erbium-doped fiber amplifiers (EDFA) are one of the most important fiber amplifiers in case of longrange optical fiber communication. They are capable of amplifying the light in the wavelength region of 1.5-μm, where telecom fibres experience minimum loss. Hence Erbium-Doped Fiber Amplifier (EDFA) is used for long distances. It is found that when we increased the value of extinction ratio, the threshold value will be decreases but eye height will increases. Here in this optical design, 4 channels CWDM is simulated with various length of fiber. These days the demand for large bandwidth is continuously increasing. In order to fulfil this need, telecommunication companies have to investigate on increasing their channels capacity with the lowest cost possible.

2024, IEEE Photonics Technology Letters

We analyze by simulation the performance of an optically amplified uncompensated duobinary system using a 64-state maximum-likelihood sequence estimation (MLSE) receiver (Rx) based on a Euclidean branch metric with variable postdetection nonlinear distortion exponent. We found that the optimum exponent depends on the accumulated dispersion, the Rx analog-to-digital converter (ADC) resolution, and signal clipping. On the other hand, we found performance to be weakly dependent on the exponent value. When using a finite number of ADC resolution bits, drastic signal clipping proved very beneficial in improving the performance of the MLSE processor. Assuming three resolution bits, with joint clipping and exponent optimization, uncompensated transmission at 10.7 Gb/s over 550 km of standard single-mode fiber could be achieved with essentially no penalty with respect to back-to-back.

2024, IEEE Photonics Technology Letters

In this paper, we introduce a new formalism to study noise enhancement induced by parametric gain in wavelengthdivision-multiplexed (WDM) systems. We also analyze the phenomenon impact in a typical long-haul, dispersion-compensated link,... more

2024, Journal of the Optical Society of America B

We present a grating pair based on Carpenter prisms whose third-order dispersion is opposite that of a traditional grating pair. A properly designed stretcher-compressor system with these gratings has the unique characteristic that it simultaneously compensates for second-and third-order dispersion as a function of grating separation, as opposed to traditional systems, which require an additional grating angle mismatch. The applicability of this design to 30-fs, millijoule-level chirped-pulse amplification is discussed.