Showing papers on "Four-wave mixing published in 1997"
TL;DR: In this article, the authors present a simple, yet powerful method for calculating nonlinear pulse propagation and pulse interaction in active semiconductor waveguides based on the density matrix equations, which under realistic operation conditions are shown to lead to an accurate description of the material gain, that includes the dynamics of carrier heating and spectral-hole burning.
Abstract: We present a simple, yet powerful method for calculating nonlinear pulse propagation and pulse interaction in active semiconductor waveguides. The model is based on the density matrix equations, which under realistic operation conditions are shown to lead to an accurate description of the material gain, that includes the dynamics of carrier heating and spectral-hole burning (SHB). A very general and compact description of the amplifier dynamics in terms of an integral equation is derived. The model is used to analyze saturation effects in short pulse amplification and nondegenerate four-wave mixing. An analytical expression for the four-wave mixing response is derived, which extends previous results to the case of short and intense pulses. Saturation of the four-wave mixing signal is shown to be strongly pulsewidth dependent due to ultrafast gain dynamics, and self-phase modulation is shown to give excessive broadening of the conjugate pulse. Finally, the impacts on the noise characteristics are calculated and shown to explain recent experimental results.
202 citations
TL;DR: In this paper, the authors define general parameters that are of relevance for signal processing applications and show how basic experiments and general simulation procedures can be used to determine optimum operating conditions for the intended applications.
Abstract: Four-wave mixing (FWM) in semiconductor optical amplifiers (SOAs) is an important tool for frequency conversion and fast optical switching in all-optical communication networks. We review the main applications of SOAs as nonlinear optical components. Concentrating on FWM, we define general parameters that are of relevance for signal processing applications. We show, how basic experiments and general simulation procedures can be used to determine optimum operating conditions for the intended applications. Besides a comprehensive investigation of FWM among continuous waves, we present new experimental results on FWM with picosecond optical pulses. A comparison of both reveals a different behavior and demonstrates that new optimization criteria and advanced theoretical models have to be applied for the case of short optical pulses. Moreover, we discuss the possibility to extract the dynamical SOA parameters from our experiments.
176 citations
TL;DR: EIT in an inhomogeneously broadened spectral hole-burning system of Pr(3+)-doped Y(2)SiO(5) at 6 K opens the possibilities of pursuing EIT applications such as high-resolution optical image processing and optical data storage in solids.
Abstract: We have demonstrated electromagnetically induced transparency (EIT) in an inhomogeneously broadened spectral hole-burning system of Pr(3+)-doped Y(2)SiO(5) at 6 K. We have also shown enhancement of four-wave mixing under conditions of reduced absorption. This demonstration opens the possibilities of pursuing EIT applications such as high-resolution optical image processing and optical data storage in solids.
144 citations
TL;DR: In this paper, a series of systems experiments evaluating several aspects of the performance of these devices at bit rates of 2.5 and 10 Gb/s are presented, including single-channel conversion over 18 nm of shift at 10 GHz, multichannel conversion, and cascaded conversions.
Abstract: Four-wave mixing (FWM) in semiconductor optical amplifiers is an attractive mechanism for wavelength conversion in wavelength-division multiplexed (WDM) systems since it provides modulation format and bit rate transparency over wide tuning ranges. A series of systems experiments evaluating several aspects of the performance of these devices at bit rates of 2.5 and 10 Gb/s are presented. Included are single-channel conversion over 18 nm of shift at 10 Gb/s, multichannel conversion, and cascaded conversions. In addition time resolved spectral analysis of wavelength conversion is presented.
131 citations
TL;DR: In this paper, a large enhancement of optical nonlinearity in one-dimensional photonic-crystal structures with a defect is considered theoretically, and it is shown that the enhancement can be obtained for absorption saturation and degenerate four-wave mixing efficiency as a result of large optical field amplitude of the localized photonic defect mode at the defect layer.
Abstract: Enhancement of optical nonlinearity in one-dimensional photonic-crystal structures with a defect is considered theoretically. It is shown that a large enhancement can be obtained for absorption saturation and degenerate four-wave mixing efficiency as a result of large optical field amplitude of the localized photonic-defect mode at the defect layer. The figure of merit of the use of the photonic-crystal structure is derived especially for systems in which the concentration of the nonlinear optical material can be arbitrarily adjusted. Optical bistability is also predicted for optically dense samples. They can be applied in real photonic devices because of their simple structure and the large enhancement obtained.
123 citations
92 citations
TL;DR: In this article, the transmission of a 4 × 10 Gbit/s OTDM data sequence is demonstrated for the first time over 406 km of non-dispersion shifted fibre.
Abstract: The transmission of a 4 × 10 Gbit/s OTDM data sequence is demonstrated for the first time over 406 km of non-dispersion shifted fibre. Four wave mixing in a 2 mm long semiconductor optical amplifier was used to compensate for dispersion via mid-span spectral inversion. A record 45 dB signal-to-noise ratio in a 0.1 nm bandwidth was obtained for the spectrally inverted signal.
86 citations
TL;DR: In this paper, the authors report an extended study on the dependence of efficiency and noise on device length, pump power, operation wavelength and conversion interval on four-wave mixing in semiconductor optical amplifiers.
Abstract: Four-wave mixing in semiconductor optical amplifiers is used to produce wavelength conversion. We report an extended study on the dependence of efficiency and noise on device length, pump power, operation wavelength and conversion interval. The use of longer active regions is a good way to obtain performance as good as requested by the most advanced telecommunication systems.
84 citations
TL;DR: Femtosecond time-resolved four-wave mixing (FWM) spectroscopy is performed using degenerate laser frequencies in order to investigate molecular dynamics in iodine molecules in the gas phase.
72 citations
22 Sep 1997
TL;DR: In this paper, a four-wave mixing in a dispersion arranged 750m highly nonlinear dispersion-shifted fiber with a nonlinear coefficient of 20.4 W-1 km-1.
Abstract: A simultaneous wavelength conversion of 200 Gb/s (5×40 Gb/s) WDM signal over the entire gain band of an Er-doped fiber amplifier (EDFA) is demonstrated by a four-wave mixing in a dispersion arranged 750-m highly nonlinear dispersion-shifted fiber with a nonlinear coefficient of 20.4 W-1 km-1. Simultaneous optical phase conjugation is also demonstrated with successful dispersion compensation in a 200 Gb/s (5×40 Gb/s) WDM transmission through a 105 km conventional single-mode fiber.
65 citations
TL;DR: In this article, an all-optical time-division demultiplexer with 22 dB conversion efficiency, using four-wave mixing (FWM) at 1550 nm in a single-mode dispersion-shifted fiber, is presented.
Abstract: We present an all-optical time-division demultiplexer with 22 dB conversion efficiency, using four-wave mixing (FWM) at 1550 nm in a single-mode dispersion-shifted fiber. Error-free demultiplexing of 20 Gb/s data to 10 Gb/s is obtained, with 1.4 dB power penalty at BER=10/sup -9/. We also derive theoretical expressions for the conversion efficiency, the maximum bit rate that is possible to demur and the shape of the switching window. In particular we emphasize the importance of phase-matching in order to achieve a flat switching window. Furthermore the pump must remain undepleted to avoid a detrimental reduction of the extinction ratio due to instantaneous parametric gain saturation.
TL;DR: Very high four-wave mixing (FWM) efficiency and signal-to-background ratio (SBR) were obtained in a 1.5mm-long bulk semiconductor optical amplifier as mentioned in this paper.
Abstract: Very high four-wave mixing (FWM) efficiency and signal-to-background ratio (SBR) are obtained in a 1.5-mm-long bulk semiconductor optical amplifier. The FWM efficiency is measured to be 5 dB at 1-THz pump-signal detuning, which is the highest value reported to date. With a pump power of -1.4 dBm, the SBR is in excess of 20 dB in a bandwidth of 12.5 GHz, for a pump-signal detuning range as large as 2 THz and the efficiency is under the same conditions larger than -1 dB for a pump-signal detuning range as large as 1 THz. These results make FWM an attractive method for practical wavelength conversion. Some low-detuning measurements show a maximum efficiency around 8 GHz.
Abstract: This paper deals with a general problem concerning semiconductor-laser amplifiers used for frequency conversion. The amplified spontaneous emission (ASE) of a saturated amplifier is investigated experimentally and theoretically. An analytical solution accounting for the spatial dependence of the inversion parameter as well as the spectral dependence of the ASE is derived. Hence, the results can be applied to arbitrary saturation conditions and frequency shifts. Our theory is applied to frequency converters based on four-wave mixing and is found to be in good agreement with both the numerical results and the experimental data. In order to quantify the performance of a frequency converter, a noise figure is defined and shown to be strongly dependent on the frequency detuning and the power of the input waves.
TL;DR: In this paper, a new technique for mapping the distribution of the zero-dispersion wavelength in a span of optical fiber is described, which is based on four-wave mixing of short pulses.
Abstract: We describe a new technique for mapping the distribution of the zero-dispersion wavelength in a span of optical fiber. With this technique, which is based on four-wave mixing of short pulses, we obtained a spectral accuracy of /spl plusmn/0.2 nm and a spatial resolution of 700 m. Theoretical analysis agrees well with experimental results and points to an order of magnitude improvement in spatial resolution using shorter pulses. Spatial resolutions less than 100 m may be necessary because we find, by destructive measurements, variations in lambda-zero by as much as 0.5 nm over spans of 500 m.
TL;DR: In this paper, an MQW SOA which has been designed for four-wave mixing (FWM) applications is reported, and a 2 mm device was able to perform wavelength conversion over 24.6 nm.
Abstract: An MQW SOA which has been designed for four-wave-mixing (FWM) applications is reported. In 40 Gbit/s system experiments, a 2 mm device was able to perform wavelength conversion over 24.6 nm. This is the largest reported wavelength translation at 40 Gbit/s using FWM in an SOA.
TL;DR: Generation of phase-conjugate light with no wavelength shift that utilizes four-wave mixing (FWM) with two orthogonal pump beams with dispersion-shifted fiber as an optical nonlinear medium is discussed.
Abstract: Generation of phase-conjugate light with no wavelength shift that utilizes four-wave mixing (FWM) with two orthogonal pump beams is discussed. Owing to the polarization properties of nondegenerate FWM, phase-conjugate light generated at the original signal wavelength can be obtained. An experiment using dispersion-shifted fiber as an optical nonlinear medium confirms the proposed scheme.
TL;DR: In this article, a perturbation theory for calculating the effects of saturation on nondegenerate four-wave mixing between short optical pulses in a semiconductor optical amplifier was developed.
Abstract: We develop a perturbation theory for calculating the effects of saturation on nondegenerate four-wave mixing between short optical pulses in a semiconductor optical amplifier. Saturation due to ultrafast intraband dynamics like carrier heating and spectral hole burning is found to be important for pulses on the order of 10-20 ps or less.
TL;DR: In this paper, the authors characterized the conversion bandwidth of a four-wave mixing semiconductor optical amplifier wavelength converter with bit error-rate (BER) of <10/sup -9/
Abstract: We characterize the conversion bandwidth of a four-wave mixing semiconductor optical amplifier wavelength converter. Conversion of 10-Gb/s signals with bit-error-rate (BER) performance of <10/sup -9/ is demonstrated for wavelength down-shifts of up to 18 nm and upshifts of up to 10 nm.
TL;DR: In this paper, the authors discuss nondegenerate four-wave mixing in a lasing long-cavity /spl lambda/4-shifted DFB laser using the laser beams as pump beams.
Abstract: In this paper, we discuss nondegenerate four-wave mixing in a lasing long-cavity /spl lambda//4-shifted DFB laser using the laser beams as pump beams. A high conversion efficiency and wide conversion range were experimentally demonstrated without the assistance of Fabry-Perot resonance. Electric field profiles of the pump, signal, and conjugate beam in our /spl lambda//4-shifted DFB laser are discussed. The third-order nonlinear susceptibilities of InP-InGaAs MQW's are then estimated from the experimental results. We discuss the saturation characteristics and the ratio of the conjugate power to the amplified spontaneous emission. We show that /spl lambda//4-shifted DFB lasers are suitable for wavelength converters using nondegenerate four-wave mixing because of their ability to provide single-device operation.
TL;DR: In this paper, a 100 GHz, 1.562 /spl mu/m signal is modified by 10 Gbit/s signals to generate 1.552 /spl µ/m subchannels in a 100 Gbps signal and its error free operation is confirmed.
Abstract: All-optical time-division multiplexing is experimentally demonstrated using four-wave mixing in a semiconductor laser amplifier. A 100 GHz, 1.562 /spl mu/m signal is modified by 10 Gbit/s signals to generate 1.552 /spl mu/m subchannels in a 100 Gbit/s signal and its error free operation is confirmed.
TL;DR: In this article, two femtosecond four-wave mixing techniques were used to provide a direct probe for two-exciton dynamics in light harvesting antennae of photosynthetic bacteria and green plants.
Abstract: Two femtosecond four-wave-mixing techniques carried out using the photon echo pulse sequence with positive or negative time delays are shown to provide a direct probe for two-exciton dynamics in light-harvesting antennae of photosynthetic bacteria and green plants. The spectroscopic signatures of intramolecular and interaction-induced (intermolecular) two-exciton states are analyzed using a collective excitonic oscillator representation of the nonlinear optical response.
TL;DR: In this paper, the authors present experimental results on the measurement of the population-relaxation times of the excited states of some metalloporphyrins such as zinc meso-tetra-phenylporphyrin (ZnmTPP), zinc mesoencetra (p-methoxyphenyl) tetrabenzporphrin (ZnmpTBP), tetratollyl porphrin(TTP).
Abstract: We present experimental results on the measurement of the population-relaxation times of the excited states of some metalloporphyrins such as zinc meso-tetra-phenylporphyrin (ZnmTPP), zinc meso-tetra (p-methoxyphenyl) tetrabenzporphyrin (ZnmpTBP), tetratollylporphyrin (TTP), cobalt tetratollylporphyrin (CoTTP) and nickel tetratollylporphyrin (NiTTP) with time-resolved degenerate four-wave mixing with the incoherent emission of a nanosecond pumped-dye laser. The experiments are carried out in the counterpropagating geometry (k4=k1+k2-k3), where k1 and k2 are counterpropagating to one another and k3 is at angle θ (<90° with respect to k1). Excited-state and ground-state relaxation times are calculated based on the theoretical formalism developed by Hiromi Okamoto [J. Opt. Soc. Am. B, 10, 2353, 1993]. The signals are recorded by delaying the probe beam (k3) for different fixed delays of the backward pump beam (k2). We observe strong signal at a second peak owing to the coherence of beams k2 and k3 for samples exhibiting excited-state absorption and a narrow peak corresponding to the coherence of beams k1 and k3 for samples that do not exhibit excited-state or reverse-saturable absorption. The nonlinear absorption is studied with the Z-scan technique. From the experimental data, we estimate the relaxation times of excited states.
TL;DR: In this paper, a polarisation-insensitive wavelength converter is proposed using bi-directional nondegenerate forward four-wave mixing in a lasing DFB-LD in which the lasing beams are used as pump waves.
Abstract: A polarisation-insensitive wavelength converter is proposed using bi-directional nondegenerate forward four-wave mixing in a lasing DFB-LD in which the lasing beams are used as pump waves. The converter suppresses the polarisation sensitivity of conversion efficiency to within 0.4 dB, and demonstrates a 10 Gbit/s wavelength conversion and optical phase conjugation.
TL;DR: In this article, a novel optical generation and transport technique for millimeter-wave (mm-wave) signals by using the fiber-optic frequency-tunable comb generator having a discrete emission spectrum as the light source is proposed.
Abstract: A novel optical generation and transport technique for millimeter-wave (mm-wave) signals by using the fiber-optic frequency-tunable comb generator having a discrete emission spectrum as the light source is proposed. 60 GHz mm-wave signal generation and transmission over a 108 km-long optical fiber link at /spl lambda/=1560 nm is demonstrated. Excellent stability of both the frequency and amplitude of the mm-wave carrier is attained, so that the 3 dB linewidth is less than 0.3 kHz and the variance of the amplitude fluctuation is 0.07 dB. The advantages include tunability of the carrier frequency, handling ease, and no need for a high-speed external light modulator.
TL;DR: Efficient generation of new spectral components owing to second-order cascading in a seeded broadband beta -barium borate typeI phase-matching parametric amplifier is demonstrated.
Abstract: Efficient generation of new spectral components owing to second-order cascading in a seeded broadband β-barium borate type I phase-matching parametric amplifier is demonstrated. One can vary the number and magnitude of these components by changing amplification bandwidth (wavelength) and phase-matching conditions. The phenomenon is treated theoretically by use of a formalism developed previously for the case of cascaded self-diffraction.
TL;DR: In this article, an optical parametric loop mirror was used to separate the generated FWM waves from the input signal and pump waves without optical filtering. But this method was not suitable for the use of optical filters.
Abstract: Wavelength interchange between two wavelength-division-multiplexed optical signals based on four-wave mixing (FWM) has been proposed and successfully demonstrated with an optical parametric loop mirror which can separate the generated FWM waves from the input signal and pump waves without optical filtering.
TL;DR: In this article, a theoretical investigation of ultrafast transient four-wave mixing (FWM) of GaAs quantum wells for coherent excitation of excitons and a large number of continuum states is presented.
Abstract: We present a theoretical investigation of ultrafast transient four-wave mixing (FWM) of GaAs quantum wells for coherent excitation of excitons and a large number of continuum states. It is shown that in this case the line shape of the FWM signal is drastically altered due to an interaction-induced coupling of the exciton to all the excited continuum states. The signal is dominantly emitted at the spectral position of the exciton and decays, as a function of delay, on a time scale set by the duration of the laser pulse rather than by the intrinsic dephasing time. Nevertheless, the spectral width of the exciton line in the FWM spectrum and in the decay of the time-resolved FWM signal in real time are governed by the intrinsic excitonic dephasing rate. It is shown that for pulse durations of \ensuremath{\sim} 100 fs (for GaAs quantum wells) this behavior can be explained as the influence of the Coulomb exchange interaction, while for even shorter pulses this behavior is dominantly caused by nonlinear polarization decay.
TL;DR: Optical gain as great as 30 with nearly distortion-free beam propagation in optically dense sodium vapor, using four-wave mixing with coherent population trapping is observed.
Abstract: We observed optical gain as great as 30 with nearly distortion-free beam propagation in optically dense sodium vapor, using four-wave mixing. Moreover, 15-dB classical noise correlations were seen in the amplified probe and conjugate beams. To achieve this performance in such a strongly absorbing medium, one must suppress unwanted absorption and self-focusing effects. This is accomplished with coherent population trapping.