Nonlinear Optical Phase Conjugation Research Articles

Dispersion compensated optical amplifier in Ti-diffused PPLN ridge waveguide.

Nonlinear optical phase conjugation is known to be an effective technique for dispersion compensation in optical fibers. It requires an optical filter to separate out only the phase conjugated signal at the output to achieve signal pulse re-narrowing by its subsequent propagation through an identical medium. In this paper, a compact design, which integrates the optical phase conjugator and the filter on a single substrate of periodically poled lithium niobate and facilitates the use of a single pump source for both phase conjugation and amplification, is proposed and analyzed using computer simulations.

Possibilities of joint application of adaptive optics technique and nonlinear optical phase conjugation to compensate for turbulent distortions

The efficiency of integrating the nonlinear optical technique based on forming a reverse wavefront and the conventional adaptive optics into a unified complex (for example, for adaptive focusing of quasi-cw laser radiation) is demonstrated. Nonlinear optical phase conjugation may provide more exact information about the phase fluctuations in the corrected wavefront in comparison with the adaptive optics methods. At the same time, the conventional methods of adaptive optics provide an efficient control of a laser beam projected onto a target for a rather long time.

A Review on Organic Materials for Optical Phase Conjugation & All-optical Switches

Nonlinear optical materials with optimum properties are essential in continuous development of photonic and electro-optical devices, used in optical communications, networking, optical computation for signal processing, and data storage equipments. The changing trend is to use organic materials/dyes that exhibit exceptional nonlinear optical properties instead of conventional materials which have comparatively low nonlinear properties. These organic materials/dyes are easy to prepare in solution or solid form. The resulting organic material has a low dielectric constant, eliminating the need for poling while maintaining the refractive index. However, these organic materials have few of the drawbacks inherent in the processing of comparable inorganic materials like of intense light induced degradation or bleaching and aggregation at higher dye concentration. In order to overcome these drawbacks and for effective use of highly nonlinear dyes, the dye molecules are doped in polymer matrix. This idea of dye-doped polymer material matrix may increase the concentration of absorptive or fluorescence centers as well as the opto-chemical and opto-physical stability. In this paper, we have discussed the strategic advantages of dye-doped polymer nonlinear materials in comparison with organic and inorganic nonlinear materials for optical phase conjugation and all optical switches in future photonics technology. This was done by studying the linear optical properties and nonlinear optical Phase Conjugation properties of two azo dye-doped polymer films by considering organic dyes disperse orange (DO-25) and disperse yellow (DY-7) doped in a polymer matrix Polymethyl methacrylate methacrylic acid (PMMA-MA). The nonlinear optical phase conjugation properties are studied using Degenerate Four Wave Mixing set-up using 532 nm wavelength CW laser beam. The effect of dye concentration, intensity of backward, forward pump, and inter beam angle between IJMIE Volume 6, Issue 1 ISSN: 2249‐0558 ________________________________________________________ A Monthly Double‐Blind Peer Reviewed Refereed Open Access International e‐Journal ‐ Included in the International Serial Directories Indexed & Listed at: Ulrich's Periodicals Directory ©, U.S.A., Open J-Gage as well as in Cabell’s Directories of Publishing Opportunities, U.S.A. International Journal of Management, IT and Engineering http://www.ijmra.us

Study of Degenerate Four-Wave Mixing in Disperse Orange Dye-Doped Polymer Film

Nonlinear optical phase conjugation by degenerate four-wave mixing (DFWM) is an important technique with applications in many fields of science and technology. Phase conjugation by Degenerate four-wave mixing is observed in Disperse Orange-25 dye doped in Polymethyl methacrylate – metacrylic acid (PMMA-MA) polymer film under low-power, continuous-wave laser irradiation. A maximum phase conjugate efficiency of 0.22% has been obtained for probe beam intensity at 0.11 W/cm2. Phase conjugation is observed for both parallel- and orthogonally-polarized probe and pump beams. The maximum PC reflectivity is achieved when the angle between probe and forward pump beam is 7 degrees. The effects of dye concentration, intensity of backward, forward pump and inter beam angle between probe and forward pump beam on phase conjugation reflectivity are also studied. PC signal strength first increases and then decreases. PC reflectivity is increased by increasing the intensity of the backward and forward pump beam. The polarization and intensity profile are verified to be preserved in the conjugate signal. The predominant phase conjugation signal is attributed to the facts that reverse saturable absorption and large third order susceptibility of the dye molecules.

Phase-Regenerative Wavelength Conversion for BPSK and DPSK Signals

Phase-regenerative wavelength conversion is demonstrated experimentally. The simultaneous combination of two nonlinear optical processes, phase conjugation and frequency conversion (Bragg scattering), produces phase-sensitive gain at two new idler wavelengths in addition to the original signal wavelength. This single-stage approach does not require phase-locking of the tunable pump. At maximum pump depletion, amplitude and phase regeneration occur simultaneously.

Optical information storage using refresh via phase conjugation

In this paper we discuss the possibility for realizing an optical memory using dynamic refreshment. Via phase-correct back-coupling by means of nonlinear optical phase-conjugation, the information stored in a photorefractive crystal is incessantly read out, transmitted into an auxiliary memory and from this back into the crystal again and in this way refreshed. Practical realizations and first results are presented.

Optical storage of information via refreshing by inverse seeding (OSIRIS)

In this paper we discuss the possibility for realizing an optical memory using dynamic refreshment. Using phase-correct back coupling by means of nonlinear optical phase conjugation the information stored in a photorefractive crystal is continuously read out, transmitted into an auxiliary memory and from this back into the crystal again and is, in this way, refreshed. Practical realizations and first results are presented.

Absorbance detection of amino acids by laser wave mixing in microbore liquid chromatography

Nonlinear optical phase conjugation by degenerate four-wave mixing is demonstrated as a sensitive “absorbance” detection method for microbore high-performance liquid chromatography. An argon ion laser operating at the 488-nm line is used as the excitation light source to generate the wave-mixing signal for dabsyl-labeled amino acids. Advantages of the nonlinear laser detection method include: virtually 100% optical signal collection efficiency, generation of the signal in the form of a coherent laser beam, signal measurement against a virtually dark background, reliable detection of small absorbance values, excellent detection sensitivity for both fluorescing and non-fluorescing analytes, relatively simple one-color one-laser optical setup, and low power or energy requirements for continuous-wave or pulsed lasers. Using our one-laser one-color nonlinear laser detector for “absorbance” measurements in liquid chromatography, we report a crude preliminary “injected” detection limit of 780 fmol for glycine.

Study of non-linear optical phase conjugation in Ca by resonant degenerate four-wave mixing via bound excited states

We have studied the optical phase conjugation (OPC) effect in Ca vapour by using the resonant degenerate four-wave mixing (DFWM) technique. The effect was studied through the first excited state of Ca, 4s4p 1 P1. The depen- dence of the reflectivity on the vapour density, the buffer gas pressure and the pump beams intensity was investigated. The influence of the strong linear absorption was taken into account in a theoretical model that led to a satisfactory interpretation of the experimental results. A maximum reflectivity of 46% was measured under optimized conditions. The effect was also studied through the high-lying bound states 4p 23 P 0 , 1 , 2 . The maximum measured reflectivity was as high as for the first excited state. The effect of the oscillator strength on the reflectivity was demonstrated experimentally and interpreted with the help of a simple theoretical model.

Nonlinear optic phase conjugation

An overview of the field of nonlinear optical phase conjugation is given. The basic properties of a phase-conjugate mirror are discussed, and examples of how this technology can be applied to the areas of high-power lasers, optical communication systems, and optical data processing (including neural networks) are presented. It is shown that the massively parallel data processing capabilities inherent in nonlinear optical interactions, coupled with their passive, all-optical nature, make this class of system potentially useful for the next generations of advanced laser systems, remote sensors, and communications systems, as well as optical data processors and network systems architectures.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Detection of multipath effect using a self-pumped optical phase-conjugate filter

A new optical Fourier domain filtering scheme that combines the conventional optical space-invariant linear filtering with a self-pumped nonlinear-optical phase-conjugation technique is proposed. The new method is used for a real-time detection and channel evaluation of the multipath information needed in radar, sonar, and communication signal-processing applications. Preliminary experimental demonstrations are included.

A Simple Interferometric Method for Measuring the Fidelity of Phase Conjugated Beams

Abstract One of the most interesting properties of the process of nonlinear optical phase conjugation is the capability of compensating for aberrations. The quality of compensation can be determined by investigation of the wavefront. A simple interferometric method for measuring fidelity of phase conjugated beams which allows a quantitative evaluation with respect to the phase distribution is described. This method was used to investigate the quality of phase conjugation by four-wave mixing in saturable absorbers. Illustrative examples are presented for the case of a phase conjugating and an ordinary mirror.

Nonlinear optical phase conjugation using F+3 centers in LiF crystals

We report the experimental observation of nonlinear optical phase conjugation using F+3 centers in LiF crystals. Using a pulsed dye laser (460 nm) as pump light, a maximum phase conjugate reflectivity of about 0.1% was obtained.

Producing two-pair phase conjugate waves by Fe:LiNbO 3 crystals' higher order nonlinear effect

We use the fifth order nonlinear effect theory to explain the new phenomenon observed in our experiments, namely the two-pair conjugation waves produced by a probe wave in the process of Fe:LiNbO 3 crystals' degenerate four-wave mixing (DFWM). The result shows that there is a higher order nonlinear effect in the Fe:LiNbO creating a multi-wave mixing. This is of great significance in both pure science and application to the investigation of nonlinear optical phase conjugation.

Announcing a special issue of the IEEE journal of quantum electronics on nonlinear optical phase conjugation

Provides upcoming special issue information of interest to practitioners and researchers.

Announcing a special issue of the IEEE journal of quantum electronics on nonlinear optical phase conjugation

Provides upcoming special issue information of interest to practitioners and researchers.

Announcing a special issue of the IEEE journal of quantum electronics on nonlinear optical phase conjugation

Announcing a special issue of the IEEE journal of quantum electronics on nonlinear optical phase conjugation

Announcing a special issue of the IEEE journal of quantum electronics on nonlinear optical phase conjugation

Provides upcoming special issue information of interest to practitioners and researchers.

Wavefront Compensation With Pseudoconjugation

We discuss how novel arrangements of conventional (static /linear) optical elements can compensate for many classes of time -varying phase distortions in optical trains. Precision corner arrays, lens arrays, and K- mirror arrays are all applicable as pseudoconjugation elements in certain classes of problems. In some cases multipassing (four or more passes) of a distorting medium can offer improved performance. Although the compensation is more limited than that available from nonlinear optical phase conjugation (NOPC), problems associated with thresholds, pumps, and frequency translations are eliminated. Abstract. We discuss how novel arrangements of conventional (static/linear) optical elements can compensate for many classes of time-varying phase distortions in optical trains. Precision corner arrays, lens arrays, and K-mirror arrays are all applicable as pseudoconjugation elements in certain classes of problems. In some cases multipassing (four or more passes) of a distorting medium can offer improved performance. Although the compensation is more limited than that available from nonlinear optical phase conjugation (NOPC), problems associated with thresholds, pumps, and frequency translations are eliminated.

Compensation for channel dispersion by nonlinear optical phase conjugation

It is proposed that the process of nonlinear optical phase conjugation can be utilized to compensate for channel dispersion and hence to correct for temporal pulse broadening. Specifically, a four-wave nonlinear interaction is shown to achieve pulse renarrowing. Spectral bandwidth constraints of the input pulse are presented for typical phase-conjugate interaction parameters.