Length Of Dispersion Compensating Fiber Research Articles

Dispersion Compensation Algorithm for Single Mode Fiber

Optical fibers enable the transmission of data through a long distance at very high speed and very low latency. However, this can be limited as a result of dispersion. This paper presents a dynamic MATLAB script that can mitigate against the dispersion in a single mode fiber (SMF)by calculating the length of dispersion compensation fiber (DCF) needed to offset the dispersion. It also calculates the number of amplifiers needed and the positions the amplifiers are to be placed. The results from the MATLAB script were also authenticated using Opti system. The average Bit error rate (BER) values gotten with simulation parameters of different scenarios shown in tables 1 and 2 are 7.6857e-17 and 5.8036e-10 respectively. The average Quality factor (Q-Factor) values of 10.046203 and 7.286533 were also gotten respectively. This showed that the effect of dispersion was compensated using the DCF thus proving the validity of the script.

Generation of Q-switched-mode-locked operations in Er-doped fiber laser based on dispersion compensating fiber saturable absorber

In our work, the stable Q-switched-mode-locked (QML) operations were generated in Er-doped fiber laser based on dispersion compensating fiber (DCF) saturable absorber (SA) for the first time. Firstly, the dissipative soliton mode-locked operation was achieved in fiber laser without DCF. After that, the DCFs with different lengths were separately added into fiber laser to gradually optimize the cavity, and QML operations could be observed. When the length of DCF was 5 m, the stable QML operations at the Q-switching envelope frequency of 72.84 kHz was obtained under the pump power of 637 mW. The maximum Q-switching envelope energy was 204 nJ which was 80 times higher than pulse energy of dissipative soliton, and the pulse width was 455.7 fs which was almost one seventh of that of dissipative soliton. To our knowledge, 455.7 fs is the shortest width of a single pulse at the peak position of the temporal envelope so far. These results indicate that DCF has excellent performance in obtaining QML operations.

An optically tunable wideband optoelectronic oscillator based on a bandpass microwave photonic filter

An optoelectronic oscillator (OEO) with wideband frequency tunability and stable output based on a bandpass microwave photonic filter (MPF) has been proposed and experimentally demonstrated. Realized by cascading a finite impulse response (FIR) filter and an infinite impulse response (IIR) filter together, the tunable bandpass MPF successfully replaces the narrowband electrical bandpass filter in a conventional single-loop OEO and serves as the oscillating frequency selector. The FIR filter is based on a tunable multi-wavelength laser and dispersion compensation fiber (DCF) while the IIR filter is simply based on an optical loop. Utilizing a long length of DCF as the dispersion medium for the FIR filter also provides a long delay line for the OEO feedback cavity and as a result, optical tuning over a wide frequency range can be achieved without sacrificing the quality of the generated signal. By tuning the wavelength spacing of the multi-wavelength laser, the oscillation frequency can be tuned from 6.88 GHz to 12.79 GHz with an average step-size of 0.128 GHz. The maximum frequency drift of the generated 10 GHz signal is observed to be 1.923 kHz over 1 hour and its phase noise reaches the -112 dBc/Hz limit of our measuring equipment at 10 kHz offset frequency.

Multiwavelength Mode-Locked Fiber-Ring Laser Based on Reflective Semiconductor Optical Amplifiers

An active multiwavelength mode-locked fiber ring laser is demonstrated by exploiting cross-gain modulation in a reflective semiconductor optical amplifier. A length of dispersion-compensation fiber is incorporated in the ring cavity to enhance the multiwavelength performance. Simultaneous tunable triple-wavelength mode-locking is implemented with the pulse repetition of 10 GHz and wavelength spacing of 1.12 nm. The results provide an effective approach to fulfill all-optical clock recovery and data pattern conversion in multiwavelength for future optical communication systems.

Flat-field fiber with small relative dispersion slope for superdense wavelength-division multiplexing transmission in the <inline-formula><math altimg="none" display="inline" overflow="scroll"><mrow><mn>1480</mn><mo>-</mo><mspace width="0.3em" /><mtext>to</mtext><mspace width="0.3em" /><mn>1610</mn><mo>-</mo><mi>nm</mi></mrow></math></inline-formula> band

We report a design for a small-residual-dispersion fiber system suitable for all wavelengths in the range of 1480 to 1610 nm, which covers the entire S to L bands. It consists of a small-relative-dispersion-slope fiber (SRDSF) with a flat modal field over the central part of the core, and the corresponding dispersion-compensating fiber (DCF). The SRDSF has mode field diameter (MFD) >10 µm at wavelength 0=1.55 µm, leading to the large effective area (Aeff95 µm2) required to reduce nonlinear effects, and dispersion 9.5 ps/(km nm) with small relative dispersion slope <0.003 nm−1 at 0=1.565 µm. The DCF, which is based on the dual-core coaxial configuration, has large negative dispersion [−248 ps/(km nm) at 0=1.565 µm], leading to a large figure of merit (FOM). The dispersion slopes of these fibers are so adjusted that a small length of DCF will compensate the accumulated dispersion in the SRDSF simultaneously at all wavelengths in the range of 1480 to 1610 nm. The maximum values of the effective dispersion of the fiber system and its slope are about ±0.2 ps/(km nm) and ±0.03 ps/(km nm2), respectively, in the entire wavelength range of 1480 to 1610 nm.

Parameters optimization of high efficiency discrete Raman fiber amplifier by using the coupled steady-state equations

By using the coupled steady-state equations, we have numerically studied the characteristics optimization of Raman fiber amplifier (RFA) in a signal/pump double-passes-the-gain-medium scheme. The simulation results are in very good agreement with those of experimental data. Given a constant pumping power, the length of dispersion compensation fiber (DCF) in a RFA could be determined. The optimum design shows that the best length of the DCF is at around 3.8 ± 0.2 km in our study. This could provide both the highest signal output power and the lowest noise figure among all conditions we choose.