Nonlinear Fabry-Perot Interferometer Research Articles

Creation of Hollow-Gaussian Beam for Optical Trap by Dual-beam Nonliear Fabry-perot Interferometer

In this paper, a model of dual-beam nonlinear Fabry-Perot interferometer (DBNFPI) for creation laser hollow-Gaussian beam (HGB) is investigated. It includes a thin film of organic dye sandwiched between two optical mirrors, and irradiated by two signal and pump laser Gaussian beams. Based on the equation describing the output-input relation of intensities concerning pump intensity and the expression of the spatial intensity distribution of output signal beam (OSB), the range of pump intensity and collection of designed parameters are numerically calculated and discussed for HGB creation. These results give us the opportunity to use DBNFPI for optical trap of low-index dielectric particles.

Spatial modulation of Gaussian beam by dual-beam nonlinear Fabry-Perot interferometer

In this paper, a model of dual-beam nonlinear Fabry-Perot interferometer (DBNFPI) for laser Gaussian beam’s spatial modulation is proposed. It includes a thin film of oil red O sandwiched between two optical mirrors and is irradiated by two signal and pump laser Gaussian beams. The equation describing the output-input relation of intensities concerning pump intensity and the expression describing the spatial intensity distribution of output signal beam (OSB) are derived. The optical bistability of DBNFPI is numerically calculated with different pump intensities as well as the capability to spatially modulate the Gaussian beam is discussed. The different shapes of the OSB as: Gaussian, flat-top-Gaussian, ring-Gaussian, hollow-Gaussian, and multi-hollow-Gaussian are shown. The suitable range of pump intensity for particular shape of OSB is discussed, especially the hollow-Gaussian shape requirement for optically trapping microspheres having reflective index to be lower than that of embedding fluid.

Self-induced diffraction patterns in nonlinear Fabry-Perot interferometer on lithium niobate

The effects of self-action of light fields within Fabry-Perot interferometers based on photorefractive lithium niobate plates both, of X- and Z- cuts are experimentally investigated. Formation of one-dimensional practically regular diffractive elements within the interferometers with slightly non-parallel input and output surfaces has been demonstrated at laser light wavelength of 532 nm. It has been found that these diffractive elements are formed due to the photorefractive response of the crystal to the steady-state optical interference patterns appeared within the interferometer at multiple reflections of light beam. From the Raman-Nath far field diffraction patterns the ordinary refractive index change within the interferometer on Z-cut crystal has been estimated.

Formation of quasi-regular diffraction patterns in the nonlinear photorefractive Fabry-Perot interferometer

Formation of optical inhomogeneities under self-action of light fields in photorefractive Fabry-Perot interferometers has been experimentally investigated using the samples of Y — and Z-cut lithium niobate. For the interferometer with the Z-cut sample, it is demonstrated that spiral-shaped inhomogeneities and two-dimensional quasi-regular diffraction patterns are formed under the effect of the Gaussian beam about 1mm in diameter and the light field with a homogeneous intensity distribution.

Transformation of the amplitude profiles of coherent light beams in a nonlinear photorefractive Fabry-Perot interferometer

The transformations of the transverse profiles of laser beams in a nonlinear Fabry-Perot interferometer based on lithium niobate crystals with a surface layer doped with a combination of photorefractive impurities (iron and copper ions) have been experimentally investigated. It is demonstrated that the distribution of transmitted beam intensity significantly changes for a few seconds at milliwatt beam powers.

Two-Dimensional Nonlinear Fabry-Perot Interferometer

This study examined a possibility to use a two-dimensional nonlinear Fabry-Perot interferometer (2DNFP) as a novel information processing device. Optical bistability was realized through positive or negative feedback between heat generated by absorption of light and change in resonance condition induced by temperature-dependent refractive index. Due to heat conduction in lateral direction, “turn-on” wave propagates two-dimensionally in this device. A novel feature of this device is that the ON-state region can degenerate at suitably weak light intensity. The authors examined the function of 2DNFP as a maze solver utilizing the extension and degeneration modes, as well as its function as logic gates. “AND”, “OR”, and “NOT” gates were realized, thus the logical universality of the 2DNFP was demonstrated.

FREQUENCY CONVERSION OF COHERENT IMAGES ON INTRACAVITY MULTIWAVE MIXING

The schemes for recording and reading of dynamic holograms in conditions of nondegenerate four- and six-wave mixing in a nonlinear Fabry-Perot interferometer have been analyzed theoretically. It has been demonstrated that there is a possibility for a considerable improvement in the diffraction efficiency and angular selectivity of dynamic gratings in the interferometer compared to the off-cavity interaction. A method for the frequency conversion of coherent images with simultaneous phase conjugation has been realized experimentally.

Frequency up-conversion of coherent images by intracavity nondegenerate four-wave mixing

This work presents theoretical and experimental studies of the processes of light field transformations upon frequency-nondegenerate fourwave mixing (NFWM) in a nonlinear Fabry-Perot interferometer (FPI). The principal aims are the development of a theory for intracavity four-wave mixing in complex molecular media in conditions of scattering from dynamic gratings and resonator feedback; determination of a mechanism of light field transformations in dynamic holograms, and also by nonlinear interferometers; working out and introduction of novel nonlinear-optical methods to control the characteristics of light beams. High diffraction efficiency (up to 13.5%) with simultaneous infrared-to-visible frequency conversion of coherent images has been experimentally obtained by intracavity NFWM.

Transverse effects under four-wave coupling in the nonlinear Fabry-Perot interferometer

Specific features of the light-beam transverse structure transformation in the process of four-wave coupling in the Fabry-Perot interferometer with a resonant nonlinearity under conditions of bifurcation of the symmetry breaking and optical bistability are analyzed. The asymmetric regimes of the interaction, characterized by a difference both in the integrated transmission functions of the nonlinear interferometer for two light beams with equal intensities and in the spatial intensity distribution at the exit of the interferometer, are considered.

Semiconductor saturable absorber mirrors as mode-locking device for femtosecond lasers: nonlinear Fabry–Perot resonator approach

We propose an analytical model for ultra-short pulse generation in CW solid-state lasers with semiconductor saturable absorber-based modulators, that regards such a modulator as a nonlinear Fabry–Perot interferometer. The ways to control ultrashort pulse parameters through the modulator's parameters are shown. A stability analysis of the solutions obtained is performed.

Control of optical bistability and complex dynamics of a nonlinear interferometer

Transfer functions and dynamic characteristics of a Fabry-Perot interferometer with a multilevel resonant medium have been studied theoretically under conditions of two-frequency excitation when one of the light beams had no resonator feedback. An incoherent control method, using absorption of an independent light beam by molecules in excited energy states, has been proposed for the bistable and dynamic characteristics of a nonlinear Fabry-Perot interferometer.

Interaction of transverse wave modes and of structures in a nonlinear Fabry—Perot interferometer

The problems of coexistence of self-organising transverse field structures and transverse wave modes are considered for a thin wide-aperture semiconductor Fabry—Perot interferometer with a carrier-density mechanism of its optical nonlinearity.

Modeling of a nonlinear enhanced performance Fabry–Perot interferometer filter

The performance of a nonlinear Fabry-Perot interferometer is presented, with the finite conductivity and the thickness of the metallic mirrors taken into account. A novel nonlinear analysis is presented to compute the electromagnetic fields inside the interferometer based on a continuous-wave condition and on a backward solution of nonlinear response of the interferometer structure. Numerical results are computed and presented. The practical use of this device as an enhanced optical filter is examined. © 1997 John Wiley & Sons, Inc. Microwave Opt Technol Lett 14, 105–108, 1997

The general approach to mode-locking mechanism analysis for CW solid-state lasers with a nonlinear Fabry-P�rot interferometer

The effective mode locking of a CW solid-state laser with a nonlinear Fabry-Perot interferometer with a period matched to that of the main cavity period (mode locking by additional cavity, or coupled-cavity mode locking) is considered. The main features of the ultra-short pulse generation obtained on the basis of numerical simulations in the framework of the fluctuation model are interpreted using an analysis of nonlinear reflectivity of the interferometer. A correlation between parameter ranges for effective mode locking and self-consistent solutions of the system describing the CW ultra-short pulse generation allows one to explain a ‘discrete’ range character. A new mode-locking regime has been described and the influence of interferometer bistability on the mode-locking efficiency has been evaluated.

Pitchfork bifurcation using a two-beam nonlinear Fabry–Perot interferometer: an analytical study

A recent modal theory of nonlinear planar resonators is applied to the analysis of the steady transmission characteristics of the two-beam nonlinear Fabry-Perot interferometer. An analytical study, based on the planewave approximation, is presented that shows the potential applications of the device. In particular, a flip-flop mode of operation, derived from a pitchfork bifurcation, is predicted. Its salient feature is to require only positive triggering pulses.

Nonlinear-optical processes in lower-dimensional conjugated structures

Reduced dimensionality and quantum confinement in conjugated organic and polymer structures enhance the effects of electron correlation on virtual electronic excitation processes and nonlinear-optical responses. A microscopic many-electron description of the third-order susceptibilities γijkl(−ω4; ω1, ω2, ω3) of conjugated structures is reviewed for one-dimensional chains and extended to two-dimensional conjugated cyclic structures. Electron correlation effects in effectively reduced dimensions result in highly correlated π-electron virtual excitations that lead to large, ultrafast nonresonant nonlinear-optical responses. The increase of dimensionality from linear to cyclic chains is found to reduce the nonresonant isotropic third-order susceptibility γg. Resonant experimental studies of saturable absorption and optical bistability in ultrathin films of quasi-two-dimensional naphthalocyanine oligomers are also presented. In the saturable-absorption studies, the resonant nonlinear refractive index n2 was measured to be 1 × 10−4 cm2/kW in the wavelength range of operating laser diodes. Based on this result, electronic absorptive optical bistability is observed on a nanosecond time scale in a nonlinear Fabry–Perot interferometer employing the saturably absorbing naphthalocyanine film as the nonlinear-optical medium.

Nonlinear Optical Polymers: Challenges and Opportunities in Photonics

ABSTRACTIn polymer structures, highly correlated virtual excitations of the π-electrons are responsible for the exceptionally large nonresonant nonlinear optical responses observed. Extremely large resonant nonlinear optical responses are also achievable in certain π-electron systems, which can be treated as optical Bloch systems. In addition to their obvious scientific importance, these large optical nonlinearities potentially make possible the implementation of powerful, new nonlinear optical devices and systems. After a description of nonlinear optical processes in polymers, two examples are presented. First, saturable absorption and optical bistability in ultrathin organic polymer films are described, illustrative of resonant third order processes. Saturable absorption studies of glassy polymer films consisting of quasi two-dimensional conjugated disc-like structures of silicon naphthalocyanine demonstrate that on-resonance the system behaves as an optical Bloch system with a linear absorptivity coefficient α0 of 1 × 105 cm−1 and an intensity dependent refractive index n2 of 1 × 104 cm2/kW in the wavelength range of standard laser diodes. A resonant nonlinear optical response of π-electron excitations provides the nonlinear interaction essential to the onset of bistability. Electronic absorptive optical bistability is observed on a nanosecond time scale in a nonlinear Fabry-Perot interferometer employing the saturably absorbing naphthalocyanine film as the nonlinear optical medium. As a second example, the nonresonant second order process of linear electrooptic effects in poled polymer films, is discussed. For such a second order nonlinear optical process, the broken global centrosymmetry is achieved by electric field poling of a thin polymer film. With high electrooptic coefficients of 10–50 pm/V and low dielectric constants of 3–4, poled polymers have potentially great advantages over inorganic crystals as electrooptic materials. As one device illustration, the application of poled polymers in electrooptic waveguide operations is presented.

All-optical routing networks based on bistable interferometers

The possibility of using bistable nonlinear Fabry–Perot interferometers as wide-band data transparent all-optical spatial switches has been investigated. It has been shown that three such devices, switching between transmitting and reflecting states, can form a 1×4 optical routing network: controlled purely by coded header pulses, preceding the data stream. The prospects for developing the performance of switches of this type towards the level required in practical telecommunications systems are discussed.

Dichroic optical bistability in a nonlinear Fabry–Perot interferometer

It is shown that a new type of optical bistability may occur in a Fabry–Perot resonator containing a nongyrotropic cubic crystal. This instability is due to an anisotropy of the nonlinear resonance absorption in the crystal. The explicit conditions for the establishment of dichroic optical bistability are determined for cases of two-photon absorption and resonance absorption by reorientable impurity centers.

Nonlinear Fabry-Perot interferometer as an optical medium for waves traveling parallel to reflecting planes

An analysis is made of the propagation of an optical wave parallel to reflecting planes in an extended nonlinear Fabry-Perot interferometer pumped by a strong wave of the same intensity. It is shown that the nonlinear-optics self-interaction of the first wave changes drastically near certain parts of the main experimental characteristic of the interferometer, which is the dependence of the intensity of the transmitted light on the intensity of the pump wave. The acoustooptic interaction can change similarly in this interferometer.