Single-pump Fiber Optical Parametric Amplifier Research Articles

Impact of Zero-Dispersion Wavelength Fluctuations in a Coupled Dual-Core Fiber Optical Parametric Amplifier

We have studied the impact of zero dispersion wavelength (ZDW) fluctuations in coupled dual-core fiber optical parametric amplifiers (FOPAs) and compared it to the single-core single-pump FOPA. We have designed a Monte Carlo model, that simulates a multidimensional Ornstein-Uhlenbeck process, describing accurately ZDW fluctuations in single and multicore fibers. In order to validate our results we have developed an analytical model, based on Taylor expansion of the average gain and successfully compared both models, with experimental results published in the literature. We have found that a significant reduction of the impact of ZDW fluctuations can be obtained in dual-core FOPAs compared to single-core ones.

Optimized design of single-pump fiber optical parametric amplifier with highly nonlinear fiber segments using a differential evolution algorithm

Fiber optical parametric amplifiers (FOPAs) are regarded as one of the candidate optical amplifiers for future ultralong-distance, large-capacity, and high-speed optical fiber communication systems. FOPAs provide high signal gain and low noise figures compared with other optical amplifiers. However, they suffer from gain fluctuation, which restricts commercial application. Optimization of the dispersion parameters of highly nonlinear fibers (HNLFs) employed as gain media is essential because they have an immediate impact on the flatness of the amplifier. An optimization method for multiple HNLF segments using the differential evolution algorithm is proposed to minimize spectral gain variation. We theoretically yield an FOPA with an average signal gain of 20 dB and gain fluctuation

Performance Comparison of Single-Pump FOPA and LRA in a 16-channel DWDM Transmission System

Raman amplifiers and Fiber optical parametric amplifiers (FOPA) are positioned as the main future leading techniques for all-optical signal amplification. Distributed Raman amplifiers are known as the least noisy, but this type of amplifiers suffers from poor pumping efficiency at low input signal powers, therefore, discrete (lumped) Raman amplifiers (LRA) could be used instead. Both FOPAs and LRAs are the likeliest replacements of conventional EDFAs, but at this point it is not clear which of these two approaches is the most promising taking into account the quality of the amplified signal. Therefore, the goal of this article is to determine which of the two amplification techniques ensures less amplifier produced signal impairments in a 16-channel 10 Gbps dense wavelength division multiplexed (DWDM) transmission system.DOI: 10.5755/j01.eie.25.1.22740

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

110 nm versatile fiber optical parametric amplifier at 1.0 μm.

The fiber optical parametric amplifier (FOPA) has been well investigated and widely adopted at the telecommunication window, and outstanding progress has been achieved in areas such as high gain, wide bandwidths, and even flexible gain-spectrum shape. In contrast, a FOPA at the bio-favorable window, 1.0 μm, has been largely underexploited, especially for its relatively limited bandwidth. Here, we demonstrate an all-fiber single-pump FOPA at 1.0 μm with versatile performances, including ultrahigh gain (∼52 dB), wide bandwidth (∼110 nm), and good gain-spectrum flatness (∼3 dB). To showcase the practical applications, the FOPA is utilized to amplify the broadband optical image signal from a spectrally encoded microscopy, yielding a sensitivity enhancement of 47 dB. Thus, it is promising that this all-fiber versatile FOPA works well as an add-on module in boosting sensitivity for existing optical systems at a 1.0 μm window.

BER Performance of a Lumped Single-pump Fiber Optical Parametric Amplifier in a 10 Gbit/s 4-channel S-band DWDM System

Results on computer simulations of a lumped single-pump FOPA (fiber optical parametric amplifier) are presented. We demonstrate optical amplification of a 10 Gbit/s 4-channel S-band DWDM system utilizing a lumped FOPA on a 400 km long link with 80 km long inter-amplifier spans. In most of the recent papers in the field of fiber optical parametric amplifiers research the amount of amplification and the gain bandwidth are considered as the FOPA parameters. We evaluate the effectiveness of FOPA through BER parameter, which depends on both the attenuation of optical signal and the quality degradation due to dispersion, crosstalk and amplifier noise, and therefore is more suitable for evaluation of optical amplifiers in lightwave systems. Ill. 4, bibl. 9 (in English; abstracts in English, Russian and Lithuanian).

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.

Parametric amplification and phase preserving amplitude regeneration of a 640 Gbit/s RZ-DPSK signal

We report the first experimental demonstration of parametric amplification and all-optical phase-preserving amplitude regeneration for a 640 Gbit/s return-to-zero (RZ) differential phase-shift keying (DPSK) optical time division multiplexed (OTDM) signal. In the designed gain-flattened single-pump fiber optical parametric amplifier (FOPA), 620 fs short optical pulses are successfully amplified with 15 dB gain with error-free performance and less than 1 dB power penalty. Phase-preserving amplitude regeneration based on gain saturation in the FOPA is carried out for optical signals with degraded optical signal-to-noise ratio. An improvement of 2.2 dB in receiver sensitivity at a bit-error-ratio of 10(-9) has been successfully achieved after regeneration, together with 13.3 dB net gain.

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.

Pump-To-Signal Intensity Modulation Transfer Characteristics in FOPAs: Modulation Frequency and Saturation Effect

This paper reports a comprehensive study of pump-to-signal intensity modulation transfer (IMT) in single-pump fiber optic parametric amplifiers (FOPAs). In particular, the IMT is studied for the first time for high-frequency fluctuations of the pump as well as in the saturated gain regime. The IMT cut-off frequency in typical single-pump FOPAs is around 100-200 GHz. The possibilities to shift this frequency based on dispersion and nonlinearities involved in the parametric gain are discussed. The severe IMT to the signal at low modulation frequencies can be suppressed by more than 50% in the gain saturation regime with respect to the linear gain operation. Experimental results confirm the validity of the numerical study.

Asymmetric gain-saturated spectrum in fiber optical parametric amplifiers

We demonstrate experimentally and numerically an unexpected spectral asymmetry in the saturated-gain spectrum of single-pump fiber optical parametric amplifiers. The interaction between higher-order four-wave mixing products and dispersive waves radiated as an effect of third-order dispersion influences the energy transfer to the signal, depending on its detuning with respect to the pump, and breaks the symmetry of the gain expected from phase-matching considerations in unsaturated amplifiers. The asymmetry feature of the saturated spectrum is shown to particularly depend on the dispersion characteristics of the amplifier and shows local maxima for specific dispersion values.

Simple methods for crosstalk reduction in fiber optical parametric amplifiers

We propose and numerically demonstrate two simple methods for reduction of the crosstalk caused by four-wave mixing between the pump and the wavelength-division multiplexed channels in single-pump fiber optical parametric amplifier. The first one is based on a proper tuning of the WDM system from the pump wavelength and the second one uses the Stokes side rather than the anti-Stokes side in the gain band.

NUMERICAL ANALYSIS OF FIBER OPTICAL PARAMETER AMPLIFIER BASED ON TRIANGULAR PHOTONIC CRYSTAL FIBER

Fiber optic parametric amplifiers (FOPA) based on triangular photonic crystal fiber (PCF) is analyzed theoretically. Equations about parametric unsaturated gain and gain bandwidth in normal or abnormal dispersion regimes are derived. Numerical simulations are performed for single-pump and two-pump FOPAs, respectively. Comparisons with FOPAs based on dispersion-shifted fiber (DSF) and highly nonlinear fibers (HNLF) are carried out. The results show that, due to the excellent dispersion profile and nonlinearity of PCF, single-pump FOPA has higher peak gain and two-pump FOPA presents higher flat gain over wider bandwidth.

Optimization of spectrally flat and broadband single-pump fiber optic parametric amplifiers

Using well-known theory for fiber optical parametric amplifiers in the no-depletion approximation, a simple condition relating the second- and fourth-order dispersion parameters β 2 and β 4 is demonstrated which ensures ripple-free, broadband gain spectra using realistic fiber parameters. Inclusion of pump depletion gives rise to expressions which enable optimization of fiber length and the maximum achievable ripple-free gain.

Broadband fiber optical parametric amplifiers

The bandwidth of a single-pump fiber optical parametric amplifier is governed by the even orders of fiber dispersion at the pump wavelength. The amplifier can exhibit gain over a wide wavelength range when operated near the fiber's zero-dispersion wavelength. It can also be used for broadband wavelength conversion,with gain. We have experimentally obtained gain of 10-18 dB as the signal wavelength was tuned over a 35-nm bandwidth near 1560 nm.