Grating Dispersion Compensator Research Articles

Performance Analysis of Gaussian Apodized Fiber Bragg Grating (GA-FBG) Dispersion Compensator for a Long Haul Optical Fiber Link

This examination gives a complete analysis of the GA-FBG, a generally involved grating for dispersion compensation across a 150 kilometer optical link, from each point. The essential objective of this study is to distinguish how long the GA-FBG can work as an independent dissemination reimbursement gadget and how well it acts in various compensation settings. In this review, the GA-FBG is utilized as an option in contrast to the exorbitant Dispersion-Reimbursing Fiber inside the association to give a more safe optical link. The investigation delves into three specific compensation methods and studies the GA-FBG grating boundaries in light of the relative abundance of real imperatives associated with a Fiber Bragg Grating (FBG) in the design phase. Using a Piece Blunder Rate analyzer to examine the streamlined links' exhibition highlights allows us to evaluate their productivity. Results show that the GA-FBG exhibits a common dispersion compensation adequacy when the link's channel boundaries are tuned. Using gearbox over distances easily exceeding 500 km, the balanced compensation strategy delivers a remarkable Q-factor respect. Utilizing OptiSystem programming, we validate the proposed system's functional viability. The results of our study indicate that the GA-FBG is capable of efficiently counteracting dispersion, leading to an optical link that is both more economical and effective, with significant potential for extended transmission ranges.

High bandwidth profile based on fiber bragg grating dispersion compensation systems for high bit rate optical communications with long distance links

High bandwidth profile based on fiber bragg grating dispersion compensation systems for high bit rate optical communications with long distance links

Ultrafast optics with a mode-locked erbium fiber laser in the undergraduate laboratory

We describe an ultrafast optics laboratory comprising a mode-locked erbium fiber laser, autocorrelation measurements, and a free-space parallel grating dispersion compensation apparatus. The gain spectrum of Er fiber provides a broad bandwidth capable of supporting sub-100 fs pulses centered near a wavelength of 1550 nm. The fiber laser design used here produces a train of pulses at a repetition rate of 55 MHz with pulse duration as short as 108 fs. The pulse duration is measured with a homebuilt autocorrelator using a simple Michelson interferometer that takes advantage of the two-photon nonlinear response of a common silicon photodiode. To compensate for temporal stretching of the short pulse due to group velocity dispersion in the fiber, an apparatus based on a pair of parallel gratings is used for pulse compression. A detailed part that lists in the supplementary material includes previously owned and common parts used by the telecommunications industry, which helps decrease costs of the laboratory. This provides a cost-effective way to introduce the principles of ultrafast optics to undergraduate laboratories.

基于双光栅的光纤激光光谱合成关键技术研究进展(特邀)

A spectral beam combination(SBC) system with dual Multi-Layer Dielectric(MLD) grating dispersion compensation configuration, which can combine multiple fiber lasers into a common aperture beam with high beam quality and relax the linewidth requirement of the individual fiber laser, has become gradually one of the most important technique route of fiber laser beam combining. The basic principle and the key technologies of the SBC system with dual-MLD-grating configuration were introduced and analyzed briefly. The recent progress of the main key technologies about high power beam combinable narrow linewidth fiber laser, high power high efficiency short wavelength narrow linewidth fiber laser, large dispersion high efficiency MLD grating and high integration dense beam combining were reviewed. The recent progress on the key technologies of SBC with dual-MLD-configuration in Institute of Applied Electronics, China Academy of Engineering Physics, were also presented. The potential of the SBC with dual-MLD-configuration was prospected.

Characteristics of Chirped Fiber Bragg Grating Dispersion Compensator Utilizing Two Apodization Profiles

Characteristics of Chirped Fiber Bragg Grating Dispersion Compensator Utilizing Two Apodization Profiles

10.8 kW spectral beam combination of eight all-fiber superfluorescent sources and their dispersion compensation.

We report an 8-element spectral beam combination of Yb-doped all fiber superfluorescent sources around 1070 nm wavelength. Each source consists of a 60 mW front-end and a 1.5 kW three-stage fiber amplifier chain. The eight output beamlets are spectrally combined using a home-made polarization-independent multilayer dielectric reflective diffraction grating. 10.8 kW output power is achieved with an efficiency of 94%. Besides, both theoretical and experimental studies of dual grating dispersion compensation scheme have been performed, which is proved to be a prospective way for high brightness spectral beam combination.

Integrated C-band erbium-doped fiber amplifier and dispersion compensation module with negligible pump power penalty

Conventional dispersion compensation requires erbium-doped fiber amplifiers with high pump power to compensate for excess losses introduced by the dispersion-compensating fiber. We report and demonstrate an optimized single-pump amplifier configuration with a pump power penalty of less than 5% when integrated with a fiber Bragg grating dispersion compensator. The system is capable of compensating 100 km of G.652 single-mode fiber.

Grating-less, fiber-based oscillator that generates 25 nJ pulses at 80 MHz, compressible to 150 fs

We report a passively mode-locked fiber-based oscillator that has no internal dispersion-compensating gratings. This design, which we believe to be the first of its kind, produces 25 nJ pulses at 80 MHz with the pulses compressible to 150 fs. The pulses appear to be self-similar and initial data imply that their energy is further scalable.

Effects of nonideal characteristics of chirped fiber grating dispersion compensators on the system with different modulation formats

The causes leading to the nonideal characteristic of the chirped fiber Bragg grating (CFBG ) are discussed. The impact of the group delay ripple (GDR), reflectivity ripple (RR) and bandwidth of the CFBG on the 10Gb/s transmission system where non-return-to-zero (NRZ), return-to-zero (RZ) and carrier-suppressed return-to-zero (CSRZ) formats was investigated and the CFBG employed as dispersion compensator was simulated and compared in detail. The analytical result helps to optimize the practical 1500km CFBG-based transmission and the relation between the system performance and the nonideal characteristic of the grating validated the analysis in this paper.

Optimization of the apodization strength of linearly chirped Bragg gratings for span dispersion compensation

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.

A tunable four-channel fiber Bragg grating dispersion compensator

A tunable four-channel dispersion compensator is achieved using fiber Bragg grating technology and applying a temperature gradient along the grating. Any dispersion from -370 to -1420 ps/nm could be obtained.

Characteristics of Gaussian pulses transmitting in the G.652 fiber with FBG dispersion compensation

AbstractThe compression characteristics of a Gaussian pulse with varied chirp and pulse width are obtained by theoretical analysis and experiments. The compensation effects are diverse, even with the same chirped optical fiber Bragg grating (FBG) dispersion compensator, and the optimal dispersion compensation length is related to the position of the FBG. At present, in most of transmission systems, the signal from the lasers are Gaussian pulses, thus an analysis of its broader characteristics, before and after it is reflected from the FBG, will be significant. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 480–484, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11095

Influence of modulator chirp in assessing the performance implications of the group delay ripple of dispersion compensating fiber bragg gratings

The implications that the group delay ripple (GDR) of a dispersion compensating fiber Bragg grating have on transmission system performance depend on the chirp of the modulated optical signal. The wide range in the chirp properties of optical modulators and the irregular variation of the GDR over the modulated signal bandwidth make it difficult to obtain general results for the transmission performance. Using four modulators with distinct chirp properties and measured reflection spectra for two dispersion compensating gratings (DCGs), the combined effect of modulator chirp and GDR on the performance of 10-Gb/s nonreturn-to-zero dispersion compensated systems is considered. Calculated and measured results demonstrate that, to accurately assess the implications of the GDR, the chirp properties of the modulated optical signal must be considered. The relative performance obtained for distinct modulators may vary significantly, depending on the details of the chirp and GDR.

Fiber Bragg grating dispersion compensator by single-period overlap-step-scan exposure

We theoretically demonstrate that a high-quality fiber Bragg grating dispersion compensator can be fabricated by a properly designed single-period overlap-step-scan exposure method. A practical design example and a detailed tolerance analysis of this new fabrication method are given.

Strong phase-controlled fiber Bragg gratings for dispersion compensation.

Dispersion-compensating fiber Bragg gratings with approximately 99.9% reflectivity that are made by continuous apodization and phase control are demonstrated. These strong dispersion-compensating gratings provide precision second-order, third-order, or even more complex dispersion compensation, as well as sufficient transmission isolation to be used at add-drop stages without additional filtering. A 99.84% grating with a constant approximately 700-ps/nm dispersion and a 99.94% grating with dispersion varying linearly from 1000 to -1000 ps/nm are demonstrated.

Super-stretched mode-locked Yb 3+-fiber ring laser with 40 nm bandwidth, 9.5 nJ pulse energy and 630 mW output power

We report self-starting mode-locking of a diode-pumped super-stretched unidirectional ring laser based on a 26 m cladding-pumped Yb 3+-fiber and an internal grating dispersion compensation. The long fiber resulted in an extremely high pulse stretching ratio inside the cavity of about 500 which is more than one order of magnitude above previously demonstrated laser systems. This system was passively mode-locked by nonlinear polarization rotation and generated pulses with 40 nm bandwidth at 1095 nm, a pulse energy of about 9.5 nJ and an output power of 630 mW.

Design optimization of chirped sampled Bragg grating for dispersion compensation

Analytical expressions for the output pulse broadening and eye-diagram power penalty of a chirped sampled Bragg grating (CSBG) dispersion compensator are derived. The result is applied to optimize the design of residue dispersion ratio in each channel and the total channel number of a fixed-length CSBG. The optimal residue dispersion ratio does not change when the channel number changes. The filter-induced pulse distortion will induce an additional eye-diagram power penalty and will give an upper limit for the channel number of 40-G+ systems. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 171–174, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10267

Design optimization of chirped sampled Bragg grating for dispersion compensation

AbstractAnalytical expressions for the output pulse broadening and eye‐diagram power penalty of a chirped sampled Bragg grating (CSBG) dispersion compensator are derived. The result is applied to optimize the design of residue dispersion ratio in each channel and the total channel number of a fixed‐length CSBG. The optimal residue dispersion ratio does not change when the channel number changes. The filter‐induced pulse distortion will induce an additional eye‐diagram power penalty and will give an upper limit for the channel number of 40‐G+ systems. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 171–174, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10267

Analytical expression and system simulation of eye opening penalty for chirped sampled Bragg grating dispersion compensator

This paper discusses the impairment of bandwidth cutoff and group delay jump effects to eye opening penalty of chirped sampled Bragg grating dispersion compensator at 10 and 40 Gb/s theoretically. Both analytical and numerical simulation results show that bandwidth cutoff effect is the main reason for deterioration of eye opening penalty, while group delay jump effect is negligible. Cascaded transmission simulations also show that bandwidth cutoff effect does not cause the penalty deterioration apparently when span number increases.

16 x 20-Gb/s, 400-km WDM transmission over NZDSF using a slope-compensating fiber-grating module

We demonstrate 16-channel wavelength-division multiplexing transmission over nonzero dispersion-shifted fiber at a per-channel rate of 20 Gb/s. A broad-band dispersion-compensating grating module is used for compensation of dispersion and dispersion slope.