Effects of Dispersion Fiber on CWDM Directly Modulated System Performance

Campos, Carmina del Río; Horche, Paloma R.

doi:10.5772/29852

Cited by 6 publications

(6 citation statements)

References 16 publications

(9 reference statements)

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“…The spectrum characteristics provide useful information on the wavelength shift (Δλ) of the emission wavelength relative to the wavelength of the non-modulated laser. This wavelength shift is a primary cause to limitation of the WDM system performance [14,22]. Figure 4a plots the wavelength spectrum of the modulated laser signal when the laser is simulated with the small value of α = 1 under two values of ε = 0.5 × 10 -17 (small) and 5 × 10 −17 cm 3 (large).…”

Section: Theoretical Model and Simulation Methodsmentioning

confidence: 99%

“…It can be inferred that when ε increases from 0.5 × 10 -17 to 5 × 10 −17 cm 3 , δλ A increases from 0.325 to 1.23 nm, and Δλ increases from 0.212 to 2.28 nm, respectively. Such results indicate degradation in the efficiency of laser diode in WDM applications [22,37]. It is worth noting that the distinct separation between the wavelength of the "1 s" and the "0 s" (i.e.…”

Section: Theoretical Model and Simulation Methodsmentioning

confidence: 99%

“…The laser design and structure parameters that control these types of frequency chirp are the linewidth enhancement factor (α-factor) [17,18] and gain suppression [19][20][21]. The α-factor describes the refractive index variations with the injected carrier density and its impact on the dynamical properties of the LDs [22,23]. The changes in the injected carrier density induces simultaneous changes in the optical gain and refractive index of the active region, resulting in an intensity-phase coupling, which increases the laser linewidth by a factor of 1 + α 2 [17,18,24].…”

Section: Introductionmentioning

confidence: 99%

“…Although most of previous studies focused on the impact of laser chirp on the system performance, there is still room for more in-depth investigation into impacts of both α-factor and ε on the frequency chirp and the maximum fiber length, especially at a high modulation bit rate of 40-Gbps. In addition, there is a lack of studies on the influence of these parameters on the emission shifting associated with digital modulation of the laser, which is a critical issue in WDM system performance avoiding the channel interference [14,22,37].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Impact of linewidth enhancement factor and gain suppression on chirp characteristics of high-speed laser diode and performance of 40 Gbps optical fiber links

2022

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We present a simulation study on the chirping characteristics of a directly modulated 40 Gbps laser diode and evaluate its performance for use in high-speed optical fiber links. The effects of the linewidth enhancement factor (α) and gain suppression on the laser chirp and the maximum fiber transmission length are investigated. The chirp characteristics include the frequency peak-to-peak chirp of the time-varying frequency and shift of the emission wavelength. The performance of 40 Gbps optical fiber link is evaluated in terms of the eye diagram and quality factor of the received signal, which helps in predicting the maximum fiber length that achieves error-free transmission. The results show that when α increases from 1 to 10, the overshoots of the relaxation oscillations become strong, resulting in a sharp increase in laser peak-to-peak chirp from 21.8 to 205 GHz. The increase of gain suppression factor form ε = 0.5 × 10–17 cm3 to ε = 5 × 10–17 cm3 dampens out the overshoots and slightly reduces the peak-to-peak chirp from 19.5 to 193.3 GHz. Although the gain suppression works to reduce the laser chirp, it causes a significant wavelength shift relative to the emission wavelength of the non-modulated laser, which degrades the efficiency of the laser diode. On the other hand, the gain suppression is shown to increase the degree of eye-opening and the corresponding Q-factor of the fiber link on a reverse action of the linewidth enhancement factor. As fiber length increases, the influences of α and ε on chirp characteristics become more significant. The maximum fiber length (Lmax) is shown to decrease with the increase in α and/or ε; when α increases from 1 to 10, Lmax decreases from 5.89 to 0.78 km at ε = 5 × 10–17 cm3, and decreases from 2.52 to 0.3 km at ε = 0.5 × 10–17 cm3.

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Section: Theoretical Model and Simulation Methodsmentioning

confidence: 99%

Section: Theoretical Model and Simulation Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Impact of linewidth enhancement factor and gain suppression on chirp characteristics of high-speed laser diode and performance of 40 Gbps optical fiber links

2022

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“…40 Gb/s channels have begun to be implemented in new product offerings. In addition to increases in data rate per channel, the number of channels per fibre is also increased through wavelength division multiplexing (WDM) or dense WDM (DWDM) to further improve overall capacity [5]. VCSELs are semiconductor sources that emit a light beam that is perpendicular to the planes of an active region or perpendicular from the top surface of the cavity [6].…”

Section: Introductionmentioning

confidence: 99%

High Speed VCSEL Transmission at 1310 nm and 1550 nm Transmission Wavelengths

Cherutoi¹

2017

AJOP

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Vertical cavity surface emitting lasers (VCSELs) operating at 1310 nm and 1550 nm are very promising sources for access and interconnections in telecommunication systems due to their technologically attractive properties such as low threshold currents and narrow spectral linewidth due to single mode operation. VCSELs are also being rapidly commercialized for singlemode fibre metropolitan area and wide area network applications. All these advantages leads to cost-effective wavelength-tunable lasers, which are essential for the future intelligent, all-optical networks. Direct modulation (DM) of VCSEL with separate optical and current apertures enables high modulation bandwidth operating at single mode at low current density. However, dispersion and attenuation is a major hurdle to VCSELs transmission at bit rate of 10 Gb/s and above. In this study, a 1310 and 1550 nm VCSELs were directly modulated with 10 Gb/s NRZ PRBS 2 7 -1 and transmitted over 25 km ITU. T G.652 and ITU. T G.655 fibres and optimized for metro-access distances. A low dispersion penalty was realized when a 1550 nm VCSEL was used on a G.655 fibre and when a 1310 nm source was transmitted over a G.652 fibre. The transmission system has been analyzed on the basis of different parameters, which are (Bit error rate) BER, Quality (Q) factor and Output power.

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Effect of linewidth enhancement factor of laser diode and fiber dispersion management on high-speed optical fiber links performance and use in WDM systems

et al. 2023

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We present a numerical simulation study on the effect of the linewidth enhancement factor (α) of semiconductor laser and dispersion management methods of optical fibers on the performance of 40-Gb/s directly-modulated fiber links and their application in WDM systems. The dispersion management methods include the use of non-zero dispersion-shifted fiber (NZ-DSF), dispersion-compensating fiber (DCF), and fiber Bragg grating (FBG). The optimal values of the α-parameter and the best dispersion management method are applied to design and simulate a four-channel × 40-Gb/s WDM fiber system. The obtained results show that the increase in the α-parameter and/or fiber length reduces the performance of both the 40-Gb/s optical link and the WDM system. Regarding the 40-Gb/s optical link, when α = 1, using –NZ-DSF or + NZ-DSF, DCF with SSMF, and FBG with SSMF work to increase the transmission length from 1.6 km of a standard single-mode fiber (SSMF) to 7.2, 26.5, and 40 km, respectively. Whereas at α = 3.5, the maximum transmission length reaches 1.2 km when using SSMF, –NZ-DSF, or + NZ-DSF, while it increases to 13 and 35 km when using DCF with SSMF, and FBG with SSMF, respectively. In the designed WDM system, the use of FBG with SSMF is predicted as the most effective method for dispersion management. The maximum transmission length reaches 25 km when α = 1, but reduces to 12 km when α = 3.5.

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Effects of Dispersion Fiber on CWDM Directly Modulated System Performance

Cited by 6 publications

References 16 publications

Impact of linewidth enhancement factor and gain suppression on chirp characteristics of high-speed laser diode and performance of 40 Gbps optical fiber links

Impact of linewidth enhancement factor and gain suppression on chirp characteristics of high-speed laser diode and performance of 40 Gbps optical fiber links

High Speed VCSEL Transmission at 1310 nm and 1550 nm Transmission Wavelengths

Effect of linewidth enhancement factor of laser diode and fiber dispersion management on high-speed optical fiber links performance and use in WDM systems

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