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Showing papers on "Four-wave mixing published in 1994"


Journal ArticleDOI
TL;DR: Theoretical results on wave mixing in traveling-wave semiconductor laser amplifiers are presented in this article, where the authors derive equations capable of treating the range from nearly degenerate to highly nondegenerate four-wave mixing.
Abstract: Theoretical results on wave mixing in traveling-wave semiconductor laser amplifiers are presented. Starting from rather general density-matrix equations, including the effects of carrier-density pulsations, carrier heating, and spectral-hole burning, we derive equations capable of treating the range from nearly degenerate to highly nondegenerate four-wave mixing. The equations are solved numerically, and comparison to published experimental results is made. The theoretical results explain different experimental results, which have been taken to support either the role of spectral-hole burning or that of carrier heating in mediating wave mixing under highly nondegenerate conditions. >

267 citations


Journal ArticleDOI
TL;DR: In this article, a technique to design the channel frequency allocation in order to minimize the crosstalk due to FWM is presented, which is obtained at the expense of some expansion of the system bandwidth.
Abstract: Crosstalk due to four-wave mixing (FWM) is the dominant nonlinear effect in long-haul multichannel optical communication systems employing dispersion-shifted fiber. A technique to design the channel frequency allocation in order to minimize the crosstalk due to FWM is presented. It is shown that suitable unequal channel separations can be found for which no four-wave mixing product term is superimposed on any of the transmitted channels. This is obtained at the expense of some expansion of the system bandwidth. Simulations are presented to show the effectiveness of this technique in a 10-channel, 10-Gb/s per channel, system. >

263 citations


Journal ArticleDOI
TL;DR: In this article, a theoretical analysis and experimental measurements of broadband optical wavelength conversion by four-wave mixing in semiconductor traveling-wave amplifiers are presented, where both up and down-conversion efficiencies are measured as a function of wavelength shift for shifts up to 27 nm.
Abstract: We present a theoretical analysis and experimental measurements of broadband optical wavelength conversion by four-wave mixing in semiconductor traveling-wave amplifiers. In the theoretical analysis, we obtain an analytical expression for the conversion efficiency. In the experiments, both up and down-conversion efficiencies are measured as a function of wavelength shift for shifts up to 27 nm. The experimental data are well explained by the theoretical calculation. The observed higher conversion efficiency for wavelength down-conversion is believed to be caused by phase interferences that exist between various mechanisms contributing to the four-wave mixing process. >

142 citations


Journal ArticleDOI
TL;DR: In this paper, the authors describe polarization independent wavelength conversion, utilizing fiber four-wave mixing, by using two orthogonal pump lights having different frequencies, the baseband signal of the wavelength converted light is insensitive to the polarization state of the original signal light.
Abstract: This paper describes polarization independent wavelength conversion, utilizing fiber four-wave mixing. By using two orthogonal pump lights having different frequencies, the baseband signal of the wavelength converted light is insensitive to the polarization state of the original signal light. Experiments that include bit error measurements confirm the polarization independent operation. >

134 citations


Journal ArticleDOI
TL;DR: In this paper, the efficiency of broadband optical wavelength conversion by four-wave mixing in semiconductor traveling-wave amplifiers is measured for wavelength shifts up to 65 nm using a tandem amplifier geometry.
Abstract: The efficiency of broadband optical wavelength conversion by four-wave mixing in semiconductor traveling-wave amplifiers is measured for wavelength shifts up to 65 nm using a tandem amplifier geometry. A quantity we call the relative conversion efficiency function, which determines the strength of the four-wave mixing nonlinearity, was extracted from the data. Using this quantity, gain requirements for lossless four-wave mixing wavelength conversion are calculated and discussed. Signal to background noise ratio is also measured and discussed in this study. >

129 citations


Journal ArticleDOI
TL;DR: A three-pulse degenerate four-wave-mixing experiment and its theoretical analysis reveal contributions of local field and biexciton effects to the nonlinear optical response of the two-dimensional exciton, providing evidence for bieexcitonic contributions to the four- wave mixing.
Abstract: A three-pulse degenerate four-wave-mixing experiment and its theoretical analysis reveal contributions of local field and biexciton effects to the nonlinear optical response of the two-dimensional exciton. Quantum beats with a frequency equivalent to the biexciton binding energy appear only for specific polarizations. Polarization-dependent spectrally resolved four-wave mixing shows an additional peak that is separated from the 1s heavy-hole exciton line by the biexciton binding energy. These experimental results are in good agreement with the optical selection rules of the theoretical model, providing evidence for biexcitonic contributions to the four-wave mixing.

109 citations


Journal ArticleDOI
TL;DR: In this paper, the authors describe tunable wavelength conversion using fiber four-wave mixing using two pump lights, where a signal light is converted from an arbitrary frequency to another one regardless of the zero-dispersion wavelength of the fiber.
Abstract: Tunable wavelength conversion is described using fiber four-wave mixing. Utilizing two pump lights, a signal light is converted from an arbitrary frequency to another one regardless of the zero-dispersion wavelength of the fiber. Selective conversion is also possible by adjusting one of the pump light frequencies, where one of the multiplexed signals is selectively converted. >

104 citations


Journal ArticleDOI
TL;DR: The theoretical and experimental analysis reveals the importance of the excitation-induced dephasing processes for the understanding of numerous published results on polarization selections rules in FWM signals.
Abstract: The dependence of optical four-wave-mixing (FWM) signals in semiconductors on carrier density and laser-field polarization is investigated. The theoretical and experimental analysis reveals the importance of the excitation-induced dephasing processes for the understanding of numerous published results on polarization selections rules in FWM signals. Even apparently contradictory earlier findings can be explained with this theoretical model.

85 citations


Journal ArticleDOI
TL;DR: In this article, an ultrafast multiple-output all-optical time-domain demultiplexer is proposed based on multiwavelength-channel four-wave mixing with a linearly-chirped supercontinuum square pump pulse.
Abstract: A novel ultrafast multiple-output all-optical time-domain demultiplexer is proposed based on multiwavelength-channel four-wave mixing with a linearly-chirped supercontinuum square pump pulse. Error-free, simultaneous four-output, 100 Gbit/s to 6.3 Gbit/s demultiplexing of a 0.42 ps signal pulse train has been demonstrated for the first time.

80 citations



Journal ArticleDOI
TL;DR: In this article, the forward degenerate four-wave mixing in four composite samples with Cu nanoclusters embedded in fused silica was observed, and the measured third-order susceptibilities were on the order of 10−9-10−8 esu; the response time of the nonlinearity is faster than the laser pulse duration.
Abstract: We report on the observation of the forward degenerate four-wave mixing in four composite samples with Cu nanoclusters embedded in fused silica The mean diameters of the copper particles in the four samples were 5, 7, 10, and 13 nm The independent tensor elements of optical Kerr susceptibility were measured with different wave-mixing polarizations by use of 35-ps laser pulses from a mode-locked, frequency-doubled Nd:YAG laser The measured third-order susceptibilities were on the order of 10−9–10−8 esu; the response time of the nonlinearity is faster than the laser pulse duration The experimental results are consistent with a d−3 size dependence predicted for quantum-confined conduction band electrons in Cu nanoclusters

Journal ArticleDOI
TL;DR: The analytical theory of four-wave mixing in semiconductor amplifiers is developed and the conversion efficiency is the maximum at a total input power that produces a gain compression of e(-2) (approximately -9 dB), independently of the physical parameters of the amplifier.
Abstract: The analytical theory of four-wave mixing in semiconductor amplifiers is developed. The theory applies to arbitrary saturation conditions. If carrier depletion and spectral hole burning are considered, the conversion efficiency is the maximum at a total input power that produces a gain compression of e−2 (approximately −9 dB), independently of the physical parameters of the amplifier.

Journal ArticleDOI
TL;DR: In this article, the dominant effects of the biexciton-induced two-photon coherence on polarization-dependent four-wave mixing in GaAs quantum wells were demonstrated.

Journal ArticleDOI
TL;DR: In this paper, the cancellation of four-wave mixing (FWM) in multichannel optical fiber transmission is demonstrated using optical phase conjugation (OPC) in a three-channel transmission experiment along a 40 km dispersion-shifted fiber.
Abstract: The cancellation of waves generated by four-wave mixing (FWM) in multichannel optical fibre transmission is demonstrated using midway optical phase conjugation. An FWM reduction ratio of -10.6 dB is achieved in an experimental three-channel transmission experiment along a 40 km dispersion-shifted fibre.


Journal ArticleDOI
TL;DR: In this paper, a design theory of the four-wave mixing (FWM) devices using optical fibers is presented, and it is shown that the signal-to-idler conversion process in the zero-dispersion wavelength region yields the widest conversion bandwidth, and the conversion efficiency can be maximized by choosing the optimum fiber length.
Abstract: A design theory of the four-wave mixing (FWM) devices using optical fibers is presented. We find that the signal-to-idler conversion process in the zero-dispersion wavelength region yields the widest conversion bandwidth, and the conversion efficiency can be maximized by choosing the optimum fiber length. The maximum conversion efficiency thus obtained is proportional to the square of the input pump power, but is limited by the stimulated Brillouin scattering (SBS) process in the fiber. We show experimentally the improvement of the conversion efficiency by the SBS suppression and the validation of the proposed theory. >

Journal ArticleDOI
TL;DR: In this paper, a fully time-division-multiplexed 100 Gbit/s optical transmission is successfully demonstrated through a 200 km fiber, followed by PLL timing extraction and 100 to 6.3 GHz clock recovery based on polarisation-insensitive four-wave mixing.
Abstract: Fully time-division-multiplexed 100 Gbit/s optical transmission is successfully demonstrated through a 200 km fibre, followed by PLL timing extraction and 100 to 6.3 Gbit/s all-optical demultiplexing based on polarisation-insensitive four-wave mixing. The prescaled, 0.3 ps jitter 6.3 GHz clock is recovered from the 100 Gbit/s signal using the four-wave mixing light generated in a polarisation-insensitive 100 GHz laser-diode-amplifier phase detector. Polarisation-insensitive four-wave mixing demultiplexing is achieved by a polarisation rotating loop mirror configuration. >

Journal ArticleDOI
TL;DR: In this article, the optical nonlinearities of black-tea extract dissolved in water were studied using the Z-scan and the four-wave mixing techniques with 7-ns, 532-nm pulses from a Q-switched Nd:YAG laser.
Abstract: Optical nonlinearities of black-tea extract dissolved in water are studied using the Z-scan and the four-wave mixing techniques with 7-ns, 532-nm pulses from a Q-switched Nd:YAG laser. The magnitude of the third-order nonlinear optical susceptibility of tea in water is comparable with that of carbon disulfide. The nonlinearity is identified to be of thermal origin.


Journal ArticleDOI
TL;DR: In this paper, the authors investigated the origin of nonlinear gain effect in 1.5 μm active layers by using highly nondegenerate four-wave mixing, where the pump-probe detuning is extended up to 2 THz.
Abstract: The origin of the nonlinear gain effect in 1.5 μm semiconductor active layers is investigated by using highly nondegenerate four‐wave mixing, where the pump‐probe detuning is extended up to 2 THz. From the signal intensity measured as a function of the detuning frequency we find that both the spectral hole burning and the dynamic carrier heating contribute to the four‐wave mixing. The dynamic carrier heating, however, creates the index grating rather than the gain grating, and hence, the spectral hole burning is the main origin of the nonlinear gain effect.

Journal ArticleDOI
TL;DR: In this article, a four-wave mixing experiment in a bulk InGaAsP traveling-wave semiconductor amplifier is reported, where the maximum pump-probe detuning is 4.3 THz.
Abstract: A four‐wave mixing experiment in a bulk InGaAsP traveling‐wave semiconductor amplifier is reported. The maximum pump‐probe detuning is 4.3 THz. The equivalent time resolution of 37 fs is high enough to measure with good accuracy the time constant of spectral‐hole burning (100 fs in our case). The simultaneous presence of spectral‐hole burning and of an instantaneous, within our time resolution, saturation process is clearly displayed.

Journal ArticleDOI
TL;DR: Using degenerate four-wave mixing in an Fe:LiNbO(3) 0.04-wt.
Abstract: Using degenerate four-wave mixing in an Fe:LiNbO(3) 0.04-wt. % crystal and an external-reflection near-field optical microscope, we have achieved phase conjugation of light emitted by a fiber tip. We observe that the phase-conjugated light at a wavelength of 633 nm can reach a power of ~0.1 nW and produce a 180-nm-wide spot image in the near-field microscope. This is the first direct demonstration, to our knowledge, of the phase conjugation of near-field components of optical fields.

Journal ArticleDOI
TL;DR: In this article, a highly nondegenerate (up to 1 THz) four-wave mixing experiment is performed in a bulk semiconductor amplifier and a simple physical picture is given that explains the relative weight of the two saturation mechanisms in active semiconductor devices.
Abstract: A highly nondegenerate (up to 1 THz) four‐wave mixing experiment is performed in a bulk semiconductor amplifier The simultaneous presence of carrier heating and spectral hole burning shows up in a four‐wave mixing experiment A simple physical picture is given that explains the relative weight of the two saturation mechanisms in active semiconductor devices

Journal ArticleDOI
TL;DR: In this article, the authors analyzed four-wave mixing processes in bulk semiconductor optical amplifiers by comparing experimental data at detuning frequencies up to 3 THz with numerical calculations based on semiclassical density-matrix equations.
Abstract: Highly nondegenerate four‐wave mixing processes in bulk semiconductor optical amplifiers are analyzed by comparing experimental data at detuning frequencies up to 3 THz with numerical calculations based on semiclassical density‐matrix equations. Carrier heating and spectral holeburning are found to be dominant in mediating wave mixing in the THz region and lead to comparable contributions to nonlinear gain suppression in semiconductor lasers.

Journal ArticleDOI
TL;DR: In this paper, the authors studied channel crosstalk due to fiber four-wave mixing (FWM) in multichannel systems operated around the zero-dispersion wavelength.
Abstract: Channel crosstalk due to fiber four-wave mixing (FWM) in multichannel systems operated around the zero-dispersion wavelength is experimentally studied. After determining the wavelength at which FWM light is most efficiently generated, the FWM efficiency is measured for possible frequency combinations which generate FWM light at that wavelength. Using these data, FWM crosstalk in multiwavelength systems is evaluated. The results show that actual crosstalk, is less than the value estimated by the theoretical model assuming the uniformly distributed chromatic dispersion for 80-km-long fibers. It is concluded that the theoretical model can be applied to system design dealing with the worst condition. >

Journal ArticleDOI
TL;DR: In this paper, the authors measured and analyzed four-wave mixing (FWM) efficiency and fluctuation along the actual dispersion-shifted fibers (DSF's) in the short, 1.1-km DSF, their results agreed with theory, and they also obtained zero-dispersion wavelength /spl lambda//sub 0/, zero-Dispersion slope dD/d/spl lambda/, and nonlinear refractive index n/sub 2/ simultaneously.
Abstract: We measured and analysed four-wave mixing (FWM) efficiency and fluctuation along the actual dispersion-shifted fibers (DSF's). In the short, 1.1-km DSF, our results agreed with theory, and we also obtained zero-dispersion wavelength /spl lambda//sub 0/, zero-dispersion slope dD/d/spl lambda/, and nonlinear refractive index n/sub 2/ simultaneously. In the long, 23-km, DSF, a high FWM efficiency was observed in the wide wavelength region, due to the longitudinal zero-dispersion wavelength distribution. The fluctuation range was about 3.5 nm and the maximum slope about 1.1 km/nm. >

Journal ArticleDOI
TL;DR: In this paper, the distortion of a phase conjugate wave produced by degenerate four wave mixing is reported, which may impose a limiting factor in high repetition rate nonlinear devices.
Abstract: The distortion of a phase conjugate wave produced by degenerate four wave mixing as a consequence of thermal self‐defocusing is reported. The thermally induced refractive index changes cause modulation in the phase of the phase conjugate wave. The thermal self‐defocusing effect may impose a limiting factor in high repetition rate nonlinear devices.

Journal ArticleDOI
Shigeki Watanabe1, T. Chikama1
TL;DR: In this paper, a non-degenerate forward four-wave mixing in a singlemode fiber was achieved by suppressing the stimulated Brillouin scattering of pump light at a pump power of +17 dBm with an associated internal parametric gain of 3.3 dB.
Abstract: Highly efficient nondegenerate forward four-wave mixing in a singlemode fibre was achieved by suppressing the stimulated Brillouin scattering of pump light. A conversion efficiency of -4.6 dB, including a fibre loss of 5.3 dB, was obtained at a pump power of +17 dBm with an associated internal parametric gain of 3.3 dB.

Journal ArticleDOI
TL;DR: In this paper, a degenerate four-wave mixing and polarization spectroscopy method was proposed for single-pulse temperature mapping in flames by using a dual-wavelength dye laser and a diffraction grating.
Abstract: We introduce a novel and simple experimental arrangement for single-pulse two-dimensional temperature mapping in flames by the coherent imaging techniques, degenerate four-wave mixing and polarization spectroscopy, utilizing a dual-wavelength dye laser and a diffraction grating. Each pulse of this dye laser consists of two wavelengths which were tuned to resonance with two different rotational transitions in theQ1 branch of theA2∑−X2∏(0, 0) band of the OH radical. A typical coherent imaging geometry where a sheet-shaped pump beam crossed an unfocused probe beam, was used. The two generated images of OH signal distributions were spatially separated by a diffraction grating and simultaneously detected on a single CCD chip. The two-dimensional single-pulse temperature map was extracted from these images. The precision of the methods is examined and a comparison between degenerate four-wave mixing and polarization spectroscopy is made.

Journal ArticleDOI
TL;DR: In this article, a new approach to all-optical time-division multiplexing is proposed and experimentally demonstrated, where a 100 GHz 1.547 mu m signal is modified by time-delayed 6.3 Gbit/s signals to generate subchannels in a 1.557 mu m 100 Gbps/s signal via four-wave mixing.
Abstract: A new approach to all-optical time-division multiplexing is proposed and experimentally demonstrated. A 100 GHz 1.547 mu m signal is modified by time-delayed 6.3 Gbit/s signals to generate subchannels in a 1.557 mu m 100 Gbit/s signal via four-wave mixing.