Fiber Optical Parametric Amplifier Research Articles

Spectral hole in the amplified spontaneous emission spectrum of a fiber optical parametric amplifier

The amplified spontaneous emission (ASE) spectrum of a fiber optical parametric amplifier in a gain-saturation condition is studied. We experimentally observed holes around the signal and the idler in the ASE spectrum of a deeply gain-saturated amplifier. This observation is explained by a theoretical model that includes parametric interactions among ASE components and the pump, signal, and idler beams.

92% pump depletion in a continuous-wave one-pump fiber optical parametric amplifier

Theory shows that near-complete pump depletion can be obtained in uniform fiber-optic parametric amplifiers (OPA's) for a particular phase-matching condition. We have demonstrated 92% pump depletion in a cw fiber OPA, with a 200-mW pump at 1560 nm in an 11-km-long dispersion-shifted fiber.

Wavelength tunable 40 GHz pulse source based on fibre optical parametric amplifier

A simple, wavelength tunable 40 GHz RZ source based on a fibre optical parametric amplifier is demonstrated. By using a 40 GHz sinusoidally intensity modulated pump, stable, nearly chirp free, high-power, 2-4 picosecond-wide pulses are obtained over 37 nm, extended into the L-band.

Signal wavelength dependence of gain saturation in a fiber optical parametric amplifier

Signal gain-saturation characteristics in a fiber optical parametric amplifier are described. Experiments and calculations for the high-gain-saturation region are presented in which the direction of optical power transfer, which is from the pump to the signal and the idler in the unsaturated region, becomes reversed at high-signal-input powers. It is shown that the signal gain soon saturates for signal wavelengths far from the pump. This wavelength dependence is explained by the power-dependent phase mismatch and its behavior in the high-signal-input region.

Broad-band continuous-wave-pumped fiber optical parametric amplifier with 49-dB gain and wavelength-conversion efficiency

A broad-band continuous-wave (CW) pumped fiber-based parametric amplifier with 39 dB of internal gain and wavelength conversion efficiency, corresponding to a black box gain/efficiency of 38 dB, is demonstrated. Bit-error-rate (BER) measurements indicate performance comparable to erbium-doped fiber amplifiers (EDFAs). These amplifiers may thus find new applications in future lightwave systems.

Gain enhancement in cascaded fiber parametric amplifier with quasi-phase matching: theory and experiment

We report a novel gain enhancement scheme for fiber-optic parametric amplifiers utilizing cascaded amplification and quasi-phase matching (QPM). The theory and method of QPM for four-wave mixing (FWM) are developed for the first time to our knowledge. In experimental implementations of the theory, we achieve >12 dB gain improvement in a three-stage dispersion-shifted (DS) fiber parametric amplifier. A 16-dB overall gain is obtained with 11 nm separation between zero-dispersion wavelength and pump wavelength. The experimental results show good agreement with theory and simulations. The influence of QPM on spectral characteristics of parametric gain is investigated with numerical simulations.

Optical level equalisation based on gain saturation in fibre optical parametric amplifier

Optical level equalisation operation based on gain saturation in an optical fibre parametric amplifier is reported. The signal output has been measured as a function of the signal input in a fibre parametric amplifier, with the result that the signal gain saturates as the input power increases and the output power reached a maximum value at a particular input level. Utilising this gain saturation property, optical level equalisation has been demonstrated.

High-nonlinearity fiber optical parametric amplifier with periodic dispersion compensation

Theory shows that the maximum gain and bandwidth of one-pump fiber optical parametric amplifiers made from high-nonlinearity fiber, operated with a pump wavelength /spl lambda//sub p/ far from the fiber zero-dispersion wavelength /spl lambda//sub 0/ can greatly be improved by periodic dispersion compensation. We have performed experiments and obtained good agreement with theory: for /spl lambda//sub p/=1542 and /spl lambda//sub 0/=1591 nm, we have increased the bandwidth from 7 to 28 nm, and the maximum gain from 15 to 20 dB, by splicing three pieces of standard fiber at regular intervals in a 40-m long nonlinear fiber.

Demonstration of two-pump fibre optical parametric amplification

The authors demonstrate a two-pump fibre optical parametric amplifier. The pumps were pulsed, each with 2.3 W peak power. A gain of ~8 dB was observed between the pumps near 1550 nm in a 200 m long fibre, agreeing well with theory.

Broadband fiber-optical parametric amplifiers and wavelength converters with low-ripple Chebyshev gain spectra

Theory predicts that a two-pump fiber optical parametric amplifier or wavelength converter operated near the fiber zero-dispersion wavelength can exhibit a gain spectrum approximated by a Chebyshev polynomial of order 8. Under realistic conditions of pump spacing and fiber dispersion, very low-gain ripple can be obtained over a large bandwidth. For example, a dispersion-shifted fiber can provide a signal amplifier with a gain of 20 dB with 0.2-dB uniformity over a 45-nm bandwidth. Potential limitations are discussed.

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.

CW fibre optical parametric amplifier with net gain and wavelength conversion efficiency > 1

The authors have measured a signal gain of 5 dB and idler conversion efficiency of 4 dB in a CW fibre optical parametric amplifier. The broadening of the idler spectrum resulting from pump dithering used to suppress SBS is observed, and a means to eliminate it is proposed.

Fibre optical parametric amplifier operating near zero-dispersion wavelength

The authors have investigated the gain characteristics of a fibre-optical parametric amplifier operating near zero-dispersion wavelength. The gain spectrum is very sensitive to the difference between the pump and zero-dispersion wavelengths. A gain of 12 dB and an output saturation power of 8.4 dBm have been demonstrated, with a pump power of 180 mW.