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Showing papers on "Four-wave mixing published in 2004"


Journal ArticleDOI
TL;DR: Photonic crystal fibres exhibiting endlessly single-mode operation and dispersion zero in the range 1040 to 1100 nm are demonstrated.
Abstract: Photonic crystal fibres exhibiting endlessly single-mode operation and dispersion zero in the range 1040 to 1100 nm are demonstrated. A sub-ns pump source at 1064 nm generates a parametric output at 732 nm with an efficiency of 35%, or parametric gain of 55 dB at 1315 nm. A broad, flat supercontinuum extending from 500 nm to beyond 1750 nm is also demonstrated using the same pump source.

507 citations


Journal ArticleDOI
TL;DR: In this article, a time-dependent analysis of four-wave mixing in an ultraslow-propagation regime was performed and the authors obtained the analytical expressions of pulsed probe laser, FWM-generated pulse, phase shifts and absorption coefficients, group velocities, and FWM efficiency.
Abstract: We perform a time-dependent analysis of four-wave mixing (FWM) in a double-$\ensuremath{\Lambda}$ system in an ultraslow-propagation regime and obtain the analytical expressions of pulsed probe laser, FWM-generated pulse, phase shifts and absorption coefficients, group velocities, and FWM efficiency. With these analytical expressions, we show that an efficiently generated FWM field can acquire the same ultraslow group velocity $({V}_{g}∕c\ensuremath{\sim}{10}^{\ensuremath{-}4}--{10}^{\ensuremath{-}5})$ and pulse shape of a probe pump and that the maximum FWM efficiency is greater than 25%, which is orders of magnitude larger than previous FWM schemes in the ultraslow-propagation regime.

402 citations


Journal ArticleDOI
TL;DR: Low-threshold optical hyperparametric oscillations in a high-Q fluorite whispering gallery mode resonator are observed and it is demonstrated that, because of the narrow bandwidth of the resonator modes as well as the high efficiency of the resonate frequency conversion, the oscillations produce stable narrow-band beat-note of the pump, signal, and idler waves.
Abstract: We have observed low-threshold optical hyperparametric oscillations in a high-Q fluorite whispering gallery mode resonator. The oscillations result from the resonantly enhanced four-wave mixing occurring due to Kerr nonlinearity of the material. We demonstrate that, because of the narrow bandwidth of the resonator modes as well as the high efficiency of the resonant frequency conversion, the oscillations produce stable narrow-band beat-note of the pump, signal, and idler waves. A theoretical model for this process is described.

273 citations


Journal Article
TL;DR: The theoretical fundamentals of fiber-based optical parametric amplifiers (OPA) are reviewed in this article, and their applications are discussed in the end the future research aspects are expected.
Abstract: The theoretical fundamentals of fiber-based optical parametric amplifiers(OPA) are reviewed,and their applications are discussed in this paper.In the end the future research aspects are expected.

267 citations


Journal ArticleDOI
TL;DR: A two-dimensional Fourier-transform femtosecond spectroscopy technique for the visible spectral region that achieves long-term phase stability by employing diffractive optics and interferometric accuracy of excitation-pulse time delays by using movable glass wedges.
Abstract: We have developed a two-dimensional (2D) Fourier-transform femtosecond spectroscopy technique for the visible spectral region. Three-pulse photon echo signals are generated in a phase-matched noncollinear four-wave mixing box geometry that employs a 3-kHz repetition-rate laser system and optical parametric amplification. Nonlinear signals are fully characterized in amplitude and phase by spectral interferometry. Unlike for previous setups, we achieve long-term phase stability by employing diffractive optics and interferometric accuracy of excitation-pulse time delays by using movable glass wedges. As an example of this technique, 2D correlation and relaxation spectra at 600 nm are shown for a solution of Nile Blue dye in acetonitrile.

216 citations


Journal ArticleDOI
TL;DR: In this article, a multichannel pairwise four-wave mixing (FWM) scheme was proposed to achieve multiparty entanglement with perfectly efficient, ultra-low, multichannels pairwise FWM.
Abstract: We propose a scheme to achieve multiparty entanglement with perfectly efficient, ultraslow, multichannel pairwise four-wave mixing (FWM). A cold atomic medium is illuminated with an $N$-mode continuous-wave (cw) control laser to produce coherent mixtures of excited states. An ultraslowly propagating, single-photon quantum probe field completes multichannel, pairwise FWM, creating a depth dependent entanglement of $N$ Fock states. We show explicitly that this scheme can be utilized to realize an $N$-party entangled state of ultraslowly propagating quantized fields. In particular, we give the explicit analytical expression of a three-party W-state propagating at an ultraslow group velocity, and the numerical results of a multiparty W state of $2M+1$ Fock states.

153 citations


Journal ArticleDOI
TL;DR: In this article, phase-matching conditions for four-wave mixing between solitons and linear waves in optical fibers with arbitrary dispersion were derived, and the authors demonstrate resonant excitation of new spectral components via this process.
Abstract: We derive phase-matching conditions for four-wave mixing between solitons and linear waves in optical fibers with arbitrary dispersion and demonstrate resonant excitation of new spectral components via this process.

143 citations


Journal ArticleDOI
TL;DR: High-power supercontinua are demonstrated in highly nonlinear, dispersion-shifted fibers with a continuous-wave Raman fiber laser and the effect on continuum generation of parametric four-wave mixing coupled with the higher-order dispersion properties of the fiber is investigated.
Abstract: High-power supercontinua are demonstrated in highly nonlinear, dispersion-shifted fibers with a continuous-wave Raman fiber laser. Supercontinuum growth is experimentally studied under different combinations of fiber length and launch power to show output powers as high as 3.2 W and bandwidths greater than 544 nm. Modulation instability (MI) is observed to seed spectral broadening at low launch powers, and the interplay between MI and stimulated Raman scattering plays an important role in the growth of the continuum at high launch powers. The effect on continuum generation of parametric four-wave mixing coupled with the higher-order dispersion properties of the fiber is investigated.

136 citations


Posted Content
TL;DR: In this paper, phase-matching conditions for four-wave mixing between solitons and linear waves in optical fibres with arbitrary dispersion were derived, and the authors demonstrate resonant excitation of new spectral components via this process.
Abstract: We derive phase-matching conditions for four-wave mixing between solitons and linear waves in optical fibres with arbitrary dispersion and demonstrate resonant excitation of new spectral components via this process.

128 citations


Journal ArticleDOI
TL;DR: A scheme to achieve the entanglement of N photon modes (frequency modes) with perfectly efficient ultraslow multiwave mixing in a cold atomic medium with an efficient approach to realizing frequency tunability is proposed.
Abstract: We propose a scheme to achieve the entanglement of N photon modes (frequency modes) with perfectly efficient ultraslow multiwave mixing in a cold atomic medium. In addition, the method provides an efficient approach to realizing frequency tunability.

104 citations


Journal ArticleDOI
TL;DR: In this article, a lifetime-broadened four-state four-wave-mixing (FWM) scheme was proposed to acquire the same group velocity and pulse shape as those of an ultra-low pump field.
Abstract: We analyze a lifetime-broadened four-state four-wave-mixing (FWM) scheme in the ultraslow propagation regime and show that the generated FWM field can acquire the same group velocity and pulse shape as those of an ultraslow pump field. We show that a new type of induced transparency resulted from multiphoton destructive interference that significantly reduced the pump field loss. Such induced transparency based on multphoton destructive interference may have important applications in other nonlinear optical processes.

Journal ArticleDOI
TL;DR: In this article, the authors present a vector theory of four-wave mixing and use it to study the polarization-dependent nature of 4W mixing and the conditions under which the gain of a dual-pump fiber-optic parametric amplifier becomes polarization independent.
Abstract: We present a vector theory of four-wave mixing and use it to study the polarization-dependent nature of four-wave mixing and the conditions under which the gain of a dual-pump fiber-optic parametric amplifier becomes polarization independent. We find that in the absence of self- and cross-phase modulations, any pair of orthogonally polarized pumps can provide polarization-independent gain, but this gain is minimum for linearly polarized pumps and becomes maximum when the two pumps are circularly polarized. Self-and cross-phase modulations induce nonlinear polarization rotation and change the orthogonality between the two pump polarizations. We discuss the general case of elliptically polarized cases and show that only linearly and circularly polarized pumps can maintain their orthogonality along the fiber. A stability analysis shows that the case of linearly polarized pumps is more stable than the circular one against small deviations from the ideal case but that the latter provides much more amplification.

Journal ArticleDOI
TL;DR: The Manakov equation is used to study degenerate and nondegenerate four-wave mixing and the effects of linear and nonlinear wavenumber mismatches, and non linear polarization rotation, are included in the analysis.
Abstract: Parametric amplification is made possible by four-wave mixing. In low-birefringence fibers the birefringence axes and strength vary randomly with distance. Light-wave propagation in such fibers is governed by the Manakov equation. In this paper the Manakov equation is used to study degenerate and nondegenerate four-wave mixing. The effects of linear and nonlinear wavenumber mismatches, and nonlinear polarization rotation, are included in the analysis. Formulas are derived for the initial quadratic growth of the idler power, and the subsequent exponential growth of the signal and idler powers (which continues until pump depletion occurs). These formulas are valid for arbitrary pump and signal polarizations.

Journal ArticleDOI
TL;DR: In this article, the authors observed four-wave mixing in a semiconductor laser configured to emit on two wavelengths simultaneously and showed that the mixing sidebands exist up to 4 THz stemming from a modulation of the carrier plasma at the difference frequency of the two laser modes.
Abstract: We have observed four-wave mixing in a semiconductor laser configured to emit on two wavelengths simultaneously. The four-wave mixing sidebands exist up to 4 THz stemming from a modulation of the carrier plasma at the difference frequency of the two laser modes. In addition, we were able to generate and detect tunable THz radiation at this difference frequency from the laser device itself suggesting a scheme for a tunable THz source.

Journal ArticleDOI
TL;DR: In this paper, the authors applied simultaneous phase modulation to the two pump waves so that stimulated Brillouin scattering is suppressed without affecting the generated idler wave, and the signal light was converted from an arbitrary wavelength to another arbitrary one within the entire C-band.
Abstract: Highly efficient tunable wavelength conversion based on nondegenerate fiber four-wave mixing is demonstrated. We apply simultaneous phase modulation to the two pump waves so that stimulated Brillouin scattering is suppressed without affecting the generated idler wave. The signal light is converted from an arbitrary wavelength to another arbitrary one within the entire C-band with a conversion efficiency higher than -10 dB.

Journal ArticleDOI
TL;DR: In this paper, the authors reported an experimental observation of resonant four-wave mixing in cold Rb atoms, which is a type of slow-light four wave mixing at low light intensities.
Abstract: Electromagnetically induced transparency in a four-level atomic system suppresses the linear susceptibility and enhances the nonlinear susceptibilities, which leads to the resonantly enhanced slow-light four-wave mixing at low light intensities. We report an experimental observation of such resonant four-wave mixing in cold Rb atoms.

Journal ArticleDOI
TL;DR: In this article, a method of nonlinear interferometry is proposed to differentiate between which components of the anti-Stokes signal are resonant and non-resonant.
Abstract: A major impediment to the use of coherent anti-Stokes Raman scattering (CARS) to identify biological molecules is that the illumination levels required to produce a measurable signal often also produce significant nonresonant background from the medium, especially from water. We present a method of nonlinear interferometry to differentiate between which components of the anti-Stokes signal are resonant and nonresonant. The technique takes advantage of the persistence of intermediate states involved in the resonant process. This method is applicable to most existing pulsed CARS illumination methods and provides for identification of resonant CARS. We demonstrate the method by examining the signals produced by acetone, which exhibits resonance, and water, which does not.

Journal ArticleDOI
TL;DR: In this paper, the properties of an all-optical 2R regenerator based on four-wave mixing (FWM) in a semiconductor optical amplifier (SOA) are investigated.
Abstract: The properties of an all-optical 2R regenerator based on four-wave mixing (FWM) in a semiconductor optical amplifier (SOA) are investigated. The regeneration is based on the nonlinear FWM transfer function and a study of the system's static behavior reveals the operating conditions, under which the transfer function approaches most the ideal, step-like discrimination characteristic function. A fiber Bragg grating (FBG) is employed in order to overcome the SOAs speed limitations due to limited carrier dynamics. The simulations with dynamic input data by means of extinction ratio (ER) and Q-factor calculations, showed satisfactory regenerative behavior up to 40 Gb/s.

Journal ArticleDOI
TL;DR: In this article, a ten-stage cascaded wavelength conversion together with 800-km transmission for 10-Gb/s return-to-zero differential phase-shift keying (RZ-DPSK) format using four-wave mixing (FWM) in semiconductor optical amplifiers was demonstrated.
Abstract: We have demonstrated ten-stage cascaded wavelength conversion together with 800-km transmission for 10-Gb/s return-to-zero differential phase-shift keying (RZ-DPSK) format using four-wave mixing (FWM) in semiconductor optical amplifiers. To the best of our knowledge, this is the first experiment reported on cascade wavelength conversion for RZ-DPSK format, which cannot be realized by methods based on cross-gain modulation and cross-phase modulation using a semiconductor optical amplifier. Compared with wavelength conversion using FWM for conventional on-off keying format, the signal-to-pump ratio for RZ-DPSK format can be increased to higher level to achieve better performance.

Journal ArticleDOI
TL;DR: In this article, the conversion of digital and analog-modulated optical signals from the 1550nm band to the 1300nm band is demonstrated in silicon waveguides based on parametric Stokes to anti-Stokes coupling using the Raman susceptibility of silicon.
Abstract: Conversion of digital- and analog-modulated optical signals from the 1550nm band to the 1300nm band is demonstrated in silicon waveguides. The conversion is based on parametric Stokes to anti-Stokes coupling using the Raman susceptibility of silicon.

01 May 2004
TL;DR: In this paper, the authors reported an experimental observation of resonant four-wave mixing in cold Rb atoms, which is a type of slow-light four wave mixing at low light intensities.
Abstract: Electromagnetically induced transparency in a four-level atomic system suppresses the linear susceptibility and enhances the nonlinear susceptibilities, which leads to the resonantly enhanced slow-light four-wave mixing at low light intensities. We report an experimental observation of such resonant four-wave mixing in cold Rb atoms.

Journal ArticleDOI
TL;DR: Noncollinear, degenerate four-wave mixing experiments that employ a new device based on two-dimensional femtosecond pulse shaping that delays and modulates all incident fields are reported.
Abstract: We report noncollinear, degenerate four-wave mixing experiments that employ a new device based on two-dimensional femtosecond pulse shaping that delays and modulates all incident fields. Heterodyne detection is easily implemented due to the full phase stability of the device.

Journal ArticleDOI
TL;DR: In this paper, the information capacity of a wavelength-division multiplexed optical fiber communication system is estimated in a model incorporating the nonlinear propagation effects of cross-phase modulation and four-wave mixing.

Journal ArticleDOI
TL;DR: In this paper, a fractional bandwidth allocation algorithm was proposed to reduce the four-wave mixing (FWM) effect while maintaining bandwidth efficiency, where degradation caused by interchannel interference and FWM is minimal.
Abstract: A novel channel-allocation method that allows reduction of the four-wave mixing (FWM) effect while maintaining bandwidth efficiency is presented. It is composed of a fractional bandwidth-allocation algorithm, taking into consideration the use of parameters with distinct differences. This proposed technique allows the computation of an optimal channel-allocation set, where degradation caused by interchannel interference and FWM is minimal. Simulation is carried out to show significant performance improvement, such as an average bit-error rate improvement factor of 1.336 for an eight-channel wavelength-division multiplexing system, without the requirement of increased bandwidth, unlike existing channel-allocation methods.

Journal ArticleDOI
TL;DR: In this paper, the authors present an experimental study on four-wave mixing between two signals within a two-pump fiber-optical parametric amplifier (2P-FOPA) and demonstrate that the intensity of FWM spurious tones depend strongly on the signal power and length of the nonlinear medium.
Abstract: We present an experimental study on four-wave mixing (FWM) between two signals within a two-pump fiber-optical parametric amplifier (2P-FOPA). We demonstrate that the intensity of FWM spurious tones depend strongly on the signal power and length of the nonlinear medium and present two regimes as a function of the pumps' power. We also compare the amounts of FWM as a function of channel spacing in the 2P-FOPA with or without pumps and show that the presence of parametric gain enhances FWM over a broad spectral range.

Journal ArticleDOI
TL;DR: In this article, the generation of quantum-correlated photon pairs by spontaneous four-wave mixing (FWM) in an optical fiber was studied, and the influence of spontaneous Raman scattering on extracting photon pairs was experimentally investigated.
Abstract: The generation of quantum-correlated photon pairs by spontaneous four-wave mixing (FWM) in an optical fiber is studied. After demonstrating the time correlation between signal and idler photons, the influence of spontaneous Raman scattering on extracting photon pairs is experimentally investigated. It is shown that a short pulse and a narrow filtering bandwidth are preferable for obtaining correlated photon pairs with a better signal-to-noise ratio via FWM in an optical fiber.

Journal ArticleDOI
TL;DR: In this paper, a detailed theoretical analysis of four-wave mixing (FWM) wavelength conversion in quantum dot semiconductor optical amplifier (QD-SOA) is presented, taking into account the effect of the multidiscrete QD energy levels and the wetting layer.
Abstract: Detailed theoretical analysis of four-wave mixing (FWM) wavelength conversion in quantum dot semiconductor optical amplifier (QD-SOA) is presented. The model takes into account the effect of the multidiscrete QD energy levels and the wetting layer. Good agreement between calculated and experimental data is obtained. Because of the discreteness of the energy levels, QD-SOAs demonstrate high FWM conversion efficiencies at high detuning frequency. Our calculations show that carrier escape from the ground state significantly affects the performance of the amplifier.

Journal ArticleDOI
TL;DR: In this article, the authors investigate theoretically and experimentally the dynamic characteristics of the wavelength conversion that is based on four-wave mixing (FWM) in a light-holding semiconductor optical amplifier (LHSOA).
Abstract: We investigate theoretically and experimentally the dynamic characteristics of the wavelength conversion that is based on four-wave mixing (FWM) in a light-holding semiconductor optical amplifier (LHSOA). Two FWM conversion techniques, including the single-pump (SP) and two orthogonal-polarized pumps (OPP) schemes, are investigated using a sophisticated time-domain simulation model. The simulation indicates that the holding light gives an improved eye opening and signal-to-noise ratio for both the SP and OPP schemes. The chirp response for both schemes are also presented. The performance improvement are verified from dynamic measurements such as eye diagram and bit-error-rate (BER) tests. Clearer eye openings and reduced power penalties are obtained with the injection of a holding light. By comparing to the experimental results, we also prove that our numerical modeling can predict the device performance and can be used for optimizing the wavelength conversion process.

Journal ArticleDOI
TL;DR: In this paper, an additional injection beam of short wavelength was used to enhance the wavelength conversion that utilizes the four-wave mixing (FWM) effect in a semiconductor optical amplifier (SOA).
Abstract: We propose to use an additional injection beam of short wavelength to enhance the wavelength conversion that utilizes the four-wave-mixing (FWM) effect in a semiconductor optical amplifier (SOA). With this scheme, the assist light can increase the saturation intensity without sacrificing the gain of an SOA, and this leads to an increase in conversion efficiency. A numerical method dealing with various FWM mechanisms, such as amplified spontaneous emission (ASE) noise, longitudinal spatial hole burning, and wavelength-dependent gain spectrum, is developed to predict the static characteristics of our scheme. The carrier densities are nonuniformly distributed along the longitudinal direction of the SOA as a result of the ASE effect, which affects the measurement of the wavelength-dependent transparent current. The effects of an assist light on saturation output power and conversion efficiency are analyzed in detail. The analysis shows that using an assist light can improve both the conversion efficiency and signal-to-background-noise ratio (SBR) for SOAs of different lengths. The degree of improvement depends on the bias condition, assist light wavelength, and the device geometry. The study for the device optimization reveals that a compromise between conversion efficiency and SBR must be made to choose the device length.

Journal ArticleDOI
TL;DR: In this paper, a two-photon resonant non-degenerate four-wave mixing (NFWM) was studied in a dressed cascade four-level system, and the authors showed that NFWM spectrum exhibits Autler-Townes splitting, accompanied by either suppression or enhancement of the NFWM signal.
Abstract: We study two-photon resonant nondegenerate four-wave mixing (NFWM) in a dressed cascade four-level system. In the presence of a strong coupling field, the two-photon resonant NFWM spectrum exhibits Autler-Townes splitting, accompanied by either suppression or enhancement of the NFWM signal. Such phenomena are demonstrated in Ba through inducing of atomic coherence between the ground state $6{s}^{2}$ and the doubly excited autoionizing Rydberg state $6pnd$. This technique provides a spectroscopic tool for measuring not only the resonant frequency and dephasing rate but also the transition dipole moment between two highly excited atomic states.