Dual-pump Fiber Optical Parametric Amplifier Research Articles

Investigation Of Dual-Pump Fiber Optical Parametric Amplifier Performance Driven by Energy Transfer Between Four-Wave Mixing Process

Fiber optical parametric amplifier (FOPA) is operated based on energy transfer from pump waves to signal wave and at the end of the fiber, an idler wave is generated. This process is called four-wave mixing (FWM). Even though effects of higher-order dispersion coefficients, fiber length, fiber nonlinearity, fiber attenuation, pump powers, pump wavelength separation and distance of central pump wavelength with ZDW on gain profiles have been examined by previous researchers, but on different fiber or numerically studied using the Optisys system, analytical model or different amplitude equations. Thus, in this study, the above-mentioned parameters on the gain performance of dual pump fiber optical parametric amplifier (FOPA) using highly nonlinear shifted fiber (HNL-DSF) as a medium will be numerically investigated using ode45 function in Matlab. The gain at a certain wavelength can be obtained by solving 4 coupled amplitude equations with fiber loss and pump depletion that govern the four-wave mixing (FWM) process of pumps, signal and idler waves. Simulations results indicate positive gives poor or no gain, meanwhile, an addition of to negative widens the bandwidth, but there is no significant effect with the addition of . Besides, an increase of fiber length, nonlinearity and pump powers improve gain performance, but an increase of fiber loss decays the gain amplitude. Increment of pump separation will enhance flatness of gain at wavelength far from central wavelength but results in an increase of gain reduction at the central wavelength. Lastly, must be positive, not too small and not bigger than 1.125nm to get a high, broader and lesser ripples gain.

Achieving high gain using Er-Yb codoped waveguide/fiber optical parametric hybrid amplifier for dense wavelength division multiplexed system

A hybrid optical amplifier is proposed using a combination of Er-Yb codoped waveguide amplifier (EYDWA) and fiber optical parametric amplifier (FOPA). The scheme is investigated for 100 × 40 Gb / s dense wavelength division multiplexed (DWDM) system at 0.2-nm channel spacing. The parameters are optimized to achieve a flat gain of >30.6 dB, with a gain ripple of 2.67 dB. This is obtained over a wavelength range of 1542 to 1562 nm at −10-dBm optimum input power per channel, without using any costly gain flattening scheme. For higher input powers up to 10 dBm, an increase in gain ripple from 2.67 to 6.13 dB is observed. The gain ripple of 2.67 dB of the proposed EYDWA–dual pump FOPA configuration is also much better than 10.32 dB for the hybrid EYDWA–single pump FOPA. The obtained high and flat gain, along with the low noise figure, confirms the usefulness of the proposed amplifier for applications in long-haul DWDM systems.

The effect of pump parameters on dual-pump fiber optical parametric amplifier

The impact of pump parameters on dual-pump (2-P) fiber optical parametric amplifier (FOPA) is investigated. The four-wave model of coupled amplitude equations with fiber losses and pump depletion are solved numerically for the calculation of the parametric gain. Simulation results indicate that an increase in pump powers does not only enhances the parametric gain but also flattening the amplification bandwidth. Moreover, separating the pumps wavelengths further from each other can also improve the flatness of the bandwidth. Besides that, the parametric gain flatness can be improved when the separation between the pump central wavelength and zero-dispersion wavelength is small. In essence, the optimal performance of 2-P FOPA can be achieved when the pump parameters are carefully tailored.

Investigation of Dual-Pump FOPA Performance in a 4-Channel 40 Gbps WDM Transmission System

Fiber-optical parametric amplifiers (FOPA) are positioned as the future leading technique for optical signal amplification. This type of amplifiers is highly appreciated due to their applications in all-optical signal processing. Signal amplification can be achieved using single-pump or dual-pump pumping schemes. Dual-pump FOPAs provide smoother gain over wider bandwidth than single-pump FOPAs, but it is harder to maintain high performance of dual-pump FOPAs due to the stimulated Raman scattering (SRS) induced energy transfer from one pump to another. In this paper the authors investigate the performance of a dual-pump FOPA under the influence of SRS in order to ensure higher gain using as low pump power as possible in a 4-channel 40 Gbps wavelength-division multiplexed transmission system. DOI: http://dx.doi.org/10.5755/j01.eie.23.6.19699

Wideband generation of pulses in dual-pump optical parametric amplifier: theory and experiment

The generation of pulses in dual-pump fiber optical parametric amplifier is investigated. Theoretically, it is shown that in an analogical manner to pulse generation in single-pump fiber optical parametric amplifiers, the generated pulse shape depends on the linear phase mismatch between the interacting waves. However the dual-pump architecture allows for the bounding of the phase mismatch over a wide bandwidth. This feature permits the generation of uniform pulses over a wide bandwidth, contrary to the single-pump architecture. Using the developed theory, a pulse source with uniform pulses at 5 GHz repetition rate and duty cycle of 0.265 over 40 nm is demonstrated.

Dynamic Control of Gain Profile in Fiber-Optical Parametric Amplifier by Gain-Transparent SBS

We propose and experimentally demonstrate dynamic control of gain profile in a single-pump fiber-optical parametric amplifier (FOPA) assisted by gain-transparent stimulated Brillouin scattering. The FOPA gain can be enhanced/reduced through controlling the phase-matching condition without disturbing the initial parameters of the FOPA. Both the maximum and minimum gain profiles are obtained, offering operational flexibility in randomly synthesizing the profile to satisfy different requirements. Our synthesis can turn the conventional M-shaped profile into spectrally flat gain with 0.1-dB variation over 24 nm. This scheme can be potentially applied to dual-pump FOPA and can benefit other applications of parametric processes.

Gain characteristics of a dual-pump fiber optical parametric amplifier with Raman effect

We investigate the pump-depleted model of a dual-pump fiber optical parametric amplifier (FOPA) with Raman effect. As bandwidth increases, the gain profile of the distorted FOPA would be impacted seriously. Under the widebands, especially when the pump separation is large, zero dispersion wavelength (ZDW) fluctuation is another factor which can not be neglected. Numerical simulations with these comprehensive factors are mainly analyzed to obtain their influence on gain characteristics. Saturated gain spectrum is also discussed in detail.

Influence of Raman effect on the noise characteristics in a dual pump FOPA

Influence induced by Raman effect on the noise characteristics of a depleted and lossy dual pump fiber optical parametric amplifier (FOPA) is investigated. Taking the Raman effect into account, the modified coupled amplitude equations are firstly built, then the influences of Raman effect on the Stokes and anti-Stokes wavelengths with different initial signal powers are further analyzed. Besides, the effect on the FOPA gain is also shown with the same initial signal power and constant noise figure (NF).

Influence of the zero dispersion wavelength fluctuation on the gain and noise performance in dual-pump fiber parametric amplifiers

Because of the zero dispersion wavelength (ZDWL) random fluctuations, the gain and noise figures deteriorate in optical parametric amplifiers based on highly nonlinear fibers (HNLFs). The detrimental role of ZDWL fluctuations on the gain and noise performance in dual-pump fiber optical parametric amplifiers (FOPAs) is presented. Numerical investigations of noise figure (NF) for different fibers with random fluctuation are analyzed. The noise figures for different fibers are varying even if the random fluctuation is small. Through choosing HNLFs with low ZDWL fluctuation and large nonlinear coefficient, high-gain and low-noise performance can be obtained.

Multiwavelength Fiber Optical Parametric Oscillator

We demonstrate, for the first time to the best of our knowledge, a multiwavelength fiber ring laser using a continuous-wave dual-pump fiber optical parametric amplifier (FOPA) as gain medium. In the ring cavity, two high-power pumps are injected into a spool of 1-km highly nonlinear dispersion-shifted fiber to generate the parametric gain, and a superimposed chirped fiber Bragg grating is used as the comb-like filter. Benefiting from the high and flat gain of the dual-pump FOPA, seven lasing lines around 1.55 mum with wavelength spacing of 1 nm have been obtained. Each lasing line has a linewidth of as narrow as 20 pm and an extinction ratio of > 30 dB. The proposed mechanism using a dual-pump FOPA as gain medium is a promising alternative for generating multiwavelength laser.

Gain characteristic of a dual-pump fiber-optical parametric amplifier with a highly nonlinear fiber

The gain characteristic of a dual-pump fiber-optical parametric amplifier with a highly nonlinear fiber is demonstrated. The influence of various parameters on the gain spectrum of the dual-pump fiber-optical parametric amplifier is numerically simulated. The results indicate that broadband and flat gain can be obtained under optimized parameters.

Theoretical study of gain distortions in dual-pump fiber optical parametric amplifiers

We study analytically and numerically the small signal gain in dual-pump fiber optical parametric amplifiers by including the phase modulation of the pump waves needed for practically increasing the stimulated Brillouin scattering threshold. As for the single-pump case, we show that large signal gain distortions are generated under co-phase modulation, which depend on the rise/fall time of the phase modulation and on the fiber dispersion slope. However, it is clearly confirmed that the counter-phase modulation scheme allows to efficiently suppress these gain distortions over the whole flat gain region. In addition, we demonstrate through realistic numerical simulations that this useful technique overcomes the additional impact of pump-phase modulation to amplitude modulation conversion and zero-dispersion wavelength variations.

Optimization and Comparison of Single- and Dual-Pump Fiber-Optical Parametric Amplifiers with Dispersion Fluctuations

Solutions for fiber-optical parametric amplifiers (FOPAs) with dispersion fluctuations are derived using matrix operators. On the basis of the propagation matrix product and the hybrid genetic algorithm, we have optimized and compared single- and dual-pump FOPAs with zero-dispersion-wavelength variations. The simulations prove that the design of FOPAs involves multimodal function optimization problems. The numerical results show that dual-pump FOPAs are highly sensitive to dispersion fluctuations whereas dispersion variations have less impact on the gain of single-pump FOPAs. To increase signal gain and reduce ripple, dual-pump FOPAs, instead of single-pump FOPAs, have to be carefully optimized with a suitable multisegment fiber structure rather than a one-segment fiber structure. The different combinations of multisegment fibers can provide highly different gain properties. The increase in gain is at the cost of the ripple.

Gain characteristics and optimization of dual-pump fiber optical parametric amplifier using two-section highly nonlinear fibers

In this paper the gain characteristics of two-pump fiber optical parametric amplifiers (FOPA) with two-section highly nonlinear fibers are analyzed numerically and the parameters of the fibers are optimized to reach broad and flat gain spectra using genetic algorithm. Different from the previous methods, here the space between two pump wavelengths and the parameter β 4 of the fibers are included as a pivotal factor in the optimization. The numerical simulation shows that using two-section practical high nonlinear fibers, the amplifier may reach 110 nm bandwidth covering 1495–1605 nm with 10.5 dB average gain and gain ripple of 0.17 dB, when the total pump power is 1 W.

Impact of pump-phase modulation on dual-pump fiber-optic parametric amplifiers and wavelength converters

Modulation of pump phases required for suppressing stimulated-Brillouin scattering is shown to cause large power changes in both the amplified and wavelength-converted signals when dual-pump fiber-optic parametric amplifiers are used. The physical origin of power changes is related to pump-amplitude modulations caused by fiber dispersion. Analytical as well as numerical calculations show that the signal-to-noise ratio of the signal or idler may reduce to below 23 dB when pump phases change rapidly with a sharp rise time.

Noise characteristics of dual-pump fiber-optic parametric amplifiers

The noise figure (NF) properties of an undepleted and lossless dual-pump fiber-optic parametric amplifier (FOPA) are theoretically and numerically investigated. The theoretical study takes into account the noise characteristics of the two pump waves that are considered to have parallel polarization states for gain maximization. It is shown that noisy pump waves degrade the amplifier's NF, especially when the amplifier is operating at high gain values and when the input signal is high. The theoretical observations are validated by Monte Carlo numerical simulations, and the agreement between them is excellent. Finally, a comparative study concerning the noise characteristics of dual-pump and single-pump FOPAs is performed.

Pump-noise transfer in dual-pump fiber-optic parametric amplifiers:?walk-off effects

Transfer of intensity noise from pumps to signal in dual-pump fiber-optic parametric amplifiers is simulated numerically for a realistic configuration in which both pumps are amplified and filtered before they enter the fiber. The walk-off effects induced by different group velocities of pumps, signal, and idler are fully taken into account. It is found that the optical signal-to-noise ratio can be as low as 15 dB when the amplifier length is close to 0.5 km, but it can be improved by 3 dB or so by use of longer fibers.

Impact of Dispersion Fluctuations on Dual-Pump Fiber-Optic Parametric Amplifiers

Effects of zero-dispersion wavelength (ZDWL) fluctuations on dual-pump fiber-optic parametric amplifiers are investigated analytically and numerically. It is found that the signal gain varies considerably from fiber to fiber even though each fiber may have the same ZDWL on average. Moreover, the gain spectrum becomes highly nonuniform for a given fiber because of such dispersion fluctuations. Numerical simulations show that this problem can be solved to a large extent by reducing wavelength separation between the two pumps, but only at the expense of a reduced amplifier bandwidth.