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.

Raman Assisted Fiber Optical Parametric Amplifier for S-Band Multichannel Transmission System

In this paper we present results from the study of optical signal amplification using Raman assisted fiber optical parametric amplifier with considerable benefits for S-band telecommunication systems where the use of widely used erbium-doped fiber amplifier is limited. We have created detailed models and performed computer simulations of combined Raman and fiber optical parametric amplification in a 16-channel 40 Gbps/channel wavelength division multiplexed transmission system. Achieved gain bandwidth, as well as transmission system parameters—signal-to-noise ratio and bit-error-ratio—were analyzed by comparing the Raman assisted fiber optical parametric amplifier to the single pump fiber optical parametric amplifier. Results show that the 3 dB gain bandwidth in the case of combined amplification is up to 0.2 THz wider with 1.9 dB difference between the lowest and highest gain.

Pulsed entanglement measured by parametric amplifier assisted homodyne detection.

Balanced homodyne detection relies on a beam splitter to superpose the weak signal input and strong local oscillator. However, recent investigation shows that a high gain phase sensitive amplifier (PSA) can be viewed as homodyne detector, in which the strong pump of PSA serves as the local oscillator [1]. Here, we analyze a new method of measuring the continuous variable entanglement by assisting a balanced homodyne detector with the PSA and implement it experimentally. Before measuring quadrature amplitude with the balanced homodyne detectors, two entangled fields generated from a pulse pumped fiber optical parametric amplifier are simultaneously coupled into the PSA. We find that the normalized noise for both the difference and sum of the quadrature amplitudes of the two entangled fields fall below the shot noise limit by about 4.6 dB, which is the record degree of entanglement measured in optical fiber systems. The experimental results illustrate that the advantages of the new measurement method include but not limit to tolerance to detection loss and characterizing entanglement with only one homodyne detector. The influence of mode-mismatching due to multi-mode property of entanglement on the measured noise reduction can also be greatly mitigated, indicating the new method is advantageous over the traditional measurement in multi-mode case.

Gain flattened C-band hybrid optical amplifier achieving high and flat gain over 32-nm bandwidth for dense wavelength division multiplexed system

Increase in data rate demand requires continuous improvement in existing optical amplification schemes. This work demonstrates optical amplification, simulating a hybrid combination of Er-Yb codoped fiber amplifier (EYDFA) and dual pump fiber optical parametric amplifier (FOPA). The proposed EYDFA–FOPA hybrid amplifier is investigated over a wavelength range of 1533–1565 nm for 160 × 10 Gbs − 1 dense wavelength division multiplexed (DWDM) system at 0.2-nm channel spacing. The parameters are optimized to achieve a flat gain of >28.4 dB, with a gain ripple of 2.09 dB at −20 dBm optimum input power per channel. Also, analysis at different input power shows that for higher input powers up to −5 dBm, an increase in gain ripple up to 5.07 dB is observed. Further, a comparison with EYDFA–single pump FOPA configuration shows that much better gain flatness is obtained for the proposed hybrid amplifier. The obtained high and flat gain, along with the low noise figure, justifies the feasibility of the proposed amplifier for applications in broadband long-haul DWDM systems.

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.

Parametric amplification with a dual-core fiber.

In this paper we theoretically derive for the first time a matrix formalism for a coupled dual-core fiber optical parametric amplifier (FOPA). One of the most advantageous properties of this degenerate pump FOPA is the spectrally flat gain obtained when certain design parameters are met. This flat gain is obtained either in phase-sensitive (PS) or phase-insensitive (PI) operation of the dual-core FOPA. Properties such as maximum and minimum PS gain, along with maximum bandwidth and difference between maximum PS and PI gain are also investigated.

Ultra-flat wideband single-pump Raman-enhanced parametric amplification.

We experimentally optimize a single pump fiber optical parametric amplifier in terms of gain spectral bandwidth and gain variation (GV). We find that optimal performance is achieved with the pump tuned to the zero-dispersion wavelength of dispersion stable highly nonlinear fiber (HNLF). We demonstrate further improvement of parametric gain bandwidth and GV by decreasing the HNLF length. We discover that Raman and parametric gain spectra produced by the same pump may be merged together to enhance overall gain bandwidth, while keeping GV low. Consequently, we report an ultra-flat gain of 9.6 ± 0.5 dB over a range of 111 nm (12.8 THz) on one side of the pump. Additionally, we demonstrate amplification of a 60 Gbit/s QPSK signal tuned over a portion of the available bandwidth with OSNR penalty less than 1 dB for Q2 below 14 dB.

Complete temporal mode analysis in pulse-pumped fiber-optical parametric amplifier for continuous variable entanglement generation.

Mode matching plays an important role in measuring the continuous variable entanglement. For the signal and idler twin beams generated by a pulse pumped fiber optical parametric amplifier (FOPA), the spatial mode matching is automatically achieved in single mode fiber, but the temporal mode property is complicated because it is highly sensitive to the dispersion and the gain of the FOPA. We study the temporal mode structure and derive the input-output relation for each temporal mode of signal and idler beams after decomposing the joint spectral function of twin beams with the singular-value decomposition method. We analyze the measurement of the quadrature-amplitude entanglement, and find mode matching between the multi-mode twin beams and the local oscillators of homodyne detection systems is crucial to achieve a high degree of entanglement. The results show that the noise contributed by the temporal modes nonorthogonal to local oscillator may be much larger than the vacuum noise, so the mode mis-match can not be accounted for by merely introducing an effective loss. Our study will be useful for developing a source of high quality continuous variable entanglement by using the FOPA.

Fiber optical parametric amplifier with double-pass pump configuration

Characteristics of fiber optical parametric amplifier (FOPA) with double-pass pump configuration are experimentally investigated. The double-pass pump FOPA exhibits more than two-fold steeper gain slope in comparison to the conventional FOPA due to elongation of effective fiber length. In the L-band amplification band, a secondary idler is generated and used as the transmission signal in lieu of the original L-band signal. Gain measurement and bit error rate experiments are performed on the secondary idler and the results prove the usability of secondary idler, which is potentially useful for distribution networks.

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).

Fiber-Optical Parametric Amplifier With High-Speed Swept Pump

We experimentally demonstrate and characterize a high-speed frequency-swept pump in a fiber-optical parametric amplifier (FOPA). The high-speed swept pump is achieved with the swept rate as high as 78 MHz by a technique called dispersive Fourier transformation (DFT), which circumvents the fundamental speed limitation shown in the conventional swept-sources based on the cavity configurations. Based on such swept pump FOPA, the idler can be generated with a wavelength range twice the pump bandwidth. Such an all-optical approach offers an order-of-magnitude higher swept rate and thus lends itself to many applications such as high-speed signal processing and optical imaging.

Bandwidth-efficient phase modulation techniques for Stimulated Brillouin Scattering suppression in fiber optic parametric amplifiers

Two novel bandwidth efficient pump-dithering Stimulated Brillouin Scattering (SBS) suppression techniques are introduced. The techniques employ a frequency-hopped chirp and an RF noise source to impart phase modulation on the pumps of a two pump Fiber Optical Parametric Amplifier (FOPA). The effectiveness of the introduced techniques is confirmed by measurements of the SBS threshold increase and the associated improvements relative to the current state of the art. Additionally, the effect on the idler signal integrity is presented as measured following amplification from a two pump FOPA employing both techniques. The measured 0.8 dB penalty with pumps dithered by an RF noise source, after accruing 160 ps/nm of dispersion with 38 dB conversion gain in a two-pump FOPA is the lowest reported to date.

Raman-assisted fiber optical parametric amplifier and wavelength converter in highly nonlinear fiber

We present a continuous-wave pumped fiber optical parametric amplifier and wavelength converter in 1 km of highly nonlinear dispersion-shifted fiber. The reduced pump requirements of the fiber allowed a low-signal-loss configuration in which respective net gains and wavelength-conversion efficiencies of up to 8.6 dB and 5.9 dB were obtained with only 89 mW of pump power. These values were increased to 19.5 dB and 17.3 dB, respectively, when a counterpropagating 680-mW pump was used to assist the parametric process through Raman amplification. Raman assistance in highly nonlinear fiber further promotes parametric amplification and wavelength conversion as a viable technology for the future.