Nonlinear Fabry-Perot Cavity Research Articles

Effect of Surface Recombination on Diffusion Length and Active Cavity Life time

This work presents an analytical study for simulating a Fabry-Perot Bi-stable etalon (F-P cavity) filled with a dispersive optimized nonlinear optical material (Kerr type) such as semiconductors Indium Antimonite (InSb). Depending on the obtained results and because of a trade-off between the optical path length of the sample and active cavity lifetime, an optimization procedure was applied on the InSb etalon/CO laser parameters; critical switching irradiance (Ic) was applied via simulation systems of optimization procedures of optical cavity (Matlap program was used to study the optical Bi-stability of a nonlinear Fabry-Perot cavity). In order to achieve minimum switching power and faster switching time, the optimization surface recombination on the diffusion length and effective cavity lifetime was studied.
 In addition, for a specific absorption value 400 cm-1, the lifetime coefficient values were 0.33 , 0.091 , 0.0172 ns for sample thickness (D) = 500 , 60 , 20 mm, respectively. Also, for a bulk recombination time (Tl) of 200 ns, specific absorption (α) of 50 cm1, and D of 20 mm, the surface recombination speed value was 2.845 x 105 cm/sec, whereas the active lifetime, which is defined as the thickness over the surface recombination speed (sυ) (D/2sυ), was equal to 3.5ns.

Phase-Bistability and phase-locking patterns with cavity soliton in Vertical-cavity-based fast semiconductor saturable absorber

A long-wavelength-operation based phase-bistabilty and phase-locking patterns is described analytically and numerically in a nonlinear Fabry-Perot (F–P) cavity packed with fast semiconductor saturable absorber. With incident power thermo-optic effects of absorbing film and cavity heating can offer a generation of red-shifted resonances due to increase of cavity temperature. With proper signal wavelength at particular top mirror reflectivity, the cavity phase-shift in F–P cavity with saturable absorption property may enhance an X-bistabilty in phase and phase-locking patterns with cavity soliton, where the both thermal and carrier diffusion time of semiconductor materials are assumed at faster time scale (i.e. pico-second or sub-pico-second). Also, a dual cavity solitons are observed with variation of input power due to contest between absorption nonlinearity and nonlinear cavity phase-shift for temperature “rocking”.

Traveling wave formalism for the dynamics of optical systems in nonlinear Fabry–Perot cavities

We formulate the dynamics of nonlinear optical Fabry–Perot (FB) cavities in terms of a model in which only one of the two counter-propagating electric field envelopes appear. Thus, the model is simpler than the standard ones but still exact. The field envelope which propagates in the opposite direction is expressed in a very simple way in terms of the envelope that appears in the model. Thus we generalize in the simplest way to the FB case the set of Maxwell–Bloch equations for the ring cavity. The boundary condition for the field envelope that appears in the model is a simple periodicity condition. This feature allows for expanding the variables of the model in terms of traveling waves instead of standing waves as it is customary, which implies noteworthy simplifications in the calculations. On the basis of the modal equations which arise from the model, we discuss the adiabatic elimination of the atomic variables and of the atomic polarization only.

Formation of super-resolution spot through nonlinear Fabry–Perot cavity structures: theory and simulation

This study explores how interference manipulation breaks through the diffraction limit and induces super-resolution nano-optical hot spots through the nonlinear Fabry-Perot cavity structure. The theoretical analytical model is established, and the numerical simulation results show that when the thickness of the nonlinear thin film inside the nonlinear Fabry-Perot cavity structure is adjusted to centain value, the constructive interference effect can be formed in the central point of the spot, which causes the nanoscale optical hot spot in the central region to be produced. The simulation results also tell us that the hot spot size is sensitive to nonlinear thin film thickness, and the accuracy is required to be up to nanometer or even subnanometer scale, which is very large challenging for thin film deposition technique, however, slightly changing the incident laser power can compensate for drawbacks of low thickness accuracy of nonlinear thin films. Taking As(2)S(3) as the nonlinear thin film, the central hot spot with a size of 40nm is obtained at suitable nonlinear thin film thickness and incident laser power. The central hot spot size is only about λ/16, which is very useful in super-high density optical recording, nanolithography, and high-resolving optical surface imaging.

Low-switching power (

We propose a new optical bistable device (OBD), which is constructed by connecting two symmetrical fiber Bragg gratings with a ytterbium-doped fiber to form a nonlinear Fabry–Perot cavity. The principle of this new OBD is described using the transfer-matrix method, and the two groups of transmitted and reflected optical bistability loops under different parameters are investigated symmetrically. Compared with single fiber Bragg grating switching, whose switching power is greater than 2 kW, this new device has evident merits in reducing the switching power to less than 45 mW.

Numerical analysis of optical bistability based on Fiber Bragg Grating cavity containing a high nonlinearity doped-fiber

We demonstrate a new optical bistability devise by using two Fiber Bragg Gratings (FBG), in which an erbium-doped fiber (EDF) is inserted to form a nonlinear Fabry–Perot cavity (EDF FBG/F–P). The operation principle of this device is described by the resonant nonlinearity theory combining with the transfer matrix method. The optical bistability behaviors under different parameters are investigated. It shows that EDF FBG/F–P device has an evident merit in reducing the threshold switching power to 7 mW, resulting in a reduction about 6 orders, compared with that of single FBG device. Moreover, the ultra-fast response time about 35 ps is also confirmed.

Chaotically Spiking Canards in an Excitable System with 2D Inertial Fast Manifolds

We introduce a new class of excitable systems with two-dimensional fast dynamics that includes inertia. A novel transition from excitability to relaxation oscillations is discovered where the usual Hopf bifurcation is followed by a cascade of period doubled and chaotic small excitable attractors and, as they grow, by a new type of canard explosion where a small chaotic background erratically but deterministically triggers excitable spikes. This scenario is also found in a model for a nonlinear Fabry-Perot cavity with one pendular mirror.

Pedestal reduction of soliton compressed pulses by combining a nonlinear Fabry–Perot cavity and EDFA

It is well known that the pulse compressed by the high-order soliton effect in dispersion-shifted fiber (DSF) is accompanied with undesired pedestals. In this paper, based on the optical bistability effect of the nonlinear Fabry–Perot cavity (NLFPC), a novel method by combined NLFPC and EDFA is proposed for pedestal reduction. The numerical simulations demonstrate that obvious pedestal reduction can be realized by selecting reasonably the facet reflectivity of the NLFPC, and the detuning between the central frequency of the input pulse and the resonant frequency of the NLFPC.

Bogoliubov dispersion relation for a `photon fluid': Is this a superfluid?

We discuss the possibility that photons, which are bosons, can form a 2D superfluid due to Bose–Einstein condensation inside a nonlinear Fabry–Perot cavity filled with atoms in their ground states. A `photon fluid' forms inside the cavity as a result of multiple photon–photon collisions mediated by the atoms during a cavity ring-down time. The effective mass and chemical potential for a photon inside this fluid are nonvanishing. This implies the existence of a Bogoliubov dispersion relation for the low-lying elementary excitations of the photon fluid, and in particular, that sound waves exist for long-wavelength, low-frequency disturbances of this fluid. Possible experiments to test for the superfluidity of the photon fluid based on the Landau critical-velocity criterion will be discussed.

Observation of a nonlinear mode in a cylindrical Fabry–Perot cavity

We report what is believed to be the first observation of a nonlinear mode in a cylindrical nonlinear Fabry-Perot cavity. The field enhancement from cavity buildup, as well as the large chi((3)) optical nonlinearity that is due to resonantly excited (85)Rb vapor, allows the nonlinear mode to form at low incident optical powers of less than 1 mW. The mode is observed to occur for both self-focusing and self-defocusing nonlinearity.

Bose–Einstein condensation and superfluidity of a weakly-interacting photon gas in a nonlinear Fabry–Perot cavity

A field theoretical framework for the recently proposed photon condensation effect in a nonlinear Fabry–Perot cavity is discussed. The dynamics of the photon gas turns out to be described by an effective 2D Hamiltonian of a complex massive scalar field. Finite size effects turn out to be relevant for the existence of the photon condensate.

Bogoliubov dispersion relation and the possibility of superfluidity for weakly interacting photons in a two-dimensional photon fluid

The Bogoliubov dispersion relation for the elementary excitations of the weakly-interacting Bose gas is shown to hold for the case of the weakly-interacting photon gas (the ``photon fluid'') in a nonlinear Fabry-Perot cavity. This relation, which is also derived by means of a linearized fluctuation analysis in classical nonlinear optics, implies the possibility of a new superfluid state of light. The theory underlying an experiment in progress to measure this dispersion relation is described, and another experiment to test the prediction of the superfluidity of this state of light is proposed.

Optical bistability in PLZT ceramics

Optical bistability in PLZT ceramics due to the Ar+ laser induced heating and changes of the optical thickness of a plane parallel PLZT plate (behaving as the Fabry-Perot cavity) is observed. Such PLZT ceramics plate is used also as an extracavity laser mirror. Thermooptical tuning of the mirror causes a non-liner behaviour of such system. A negative feedback brought by the thermooptic mirror can be used to stabilise the laser output. On the contrary, the competitive action of the PLZT plate as the coupled mirror, on one hand, and as the non-linear Fabry-Perot cavity, on the other hand, can cause periodical fluctuations in the output of the laser.

Theoretical models of ferroelectric-photonic sensors

Abstract A theoretical model of a nonlinear Fabry-Perot cavity for a Gaussian beam with transverse diffraction is used to simulate the static and dynamic response of optical multistability in ferroelectrics. The model is applied using material parameters of ceramic lead magnesium niobate, Pb(Mg03Nb06Ti0.09)O3, for its application as photonic sensors. The theoretical results are in good agreement with the experimental results.

Finite-difference time-domain modeling of dispersive nonlinear Fabry-Perot cavities

Numerical simulations of ultrafast time-domain optical fields in nonlinear Fabry–Perot cavities are described. Thin-film cavities formed of dispersive metals and nonlinear dielectrics are modeled, and pulse-discriminating absorption is examined.

Enhanced bistability with the line-narrowed modes in a nonlinear modulated index Fabry-Perot cavity

We exploit the recently reported line narrowed modes [1] for observation of bistability in a nonlinear Fabry-Perot cavity with intracavity index modulation. We show that the frequency response of the structure exhibits larger bistability loops for the line narrowed modes.

Nonlinear Fabry–Perot cavity with chalcogenide glass thin films

An investigation of a chalcogenide glass thin-film Fabry–Perot cavity has been performed in picosecond time regime. Nonlinear behavior of the structure derives from both nonlinear absorption of the material and changes in the resonance conditions of the cavity. The conditions to have bistable behavior have been established.

Polarization induced switching and polarization bistability in non-linear Fabry-Perot resonators

The author aims at merging polarization optics and non-linear optics for non-linear Fabry-Perot cavities. The in-depth study shows, both from a stationary and a dynamical approach, that polarization modulation leads among others to a novel switching mechanism. Furthermore, in well defined circumstances, using e.g., anisotropic cavity materials, polarization optical bistability can occur. Aspects of the dynamics of these processes are highlighted and applications are suggested.

Optical limitation and bistability in fullerene

Efficient optical limitation is demonstrated in the toluene solution of C60 based on the reverse saturable absorption. The highly nonlinear absorption can be used to smooth a spike-like pulse in the nanosecond region. Optical bistability is obtained in a nonlinear Fabry–Perot cavity filled with a thin layer of polystyrene doped with C60/C70. A smooth pulse with 25 ns width (full width at half-maximum) is compressed to 15 ns and a spike-like pulse is subjected a wave form distortion by this device. The light limitation effect in this polystyrene layer 0.3 mm thick was demonstrated at the wavelength of 532 nm and the threshold about 20 mJ/cm2.

Nonlinear Interference Devices for All-optical Self-routeing

Abstract Conceptual devices for all-optical self-routeing are discussed, based on particular interference phenomena associated with modified, nonlinear Fabry-Perot cavities. The transmitted amplitude and phase are calculated for cavities composed of III-V semiconductor materials. Within the physical optics approximation the transmission of Gaussian beam profiles and their associated diffraction patterns are obtained. By engineering an asymmetry in the transmitted phase which depends upon the input intensity, an angular deflection of the beam profile can be produced under optical control. The simplest examples indicate that deflections of a beam through several degrees are theoretically feasible. Practical implementations of this effect are discussed.