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10,100
Numerical Study on Space-Time Pulse Compression
physics.optics
A numerical study of the properties of Gaussian pulses propagating in planar waveguide under the combined effect of positive Kerr-type nonlinearity, diffraction in planar waveguides and anomalous or normal dispersion, is presented. It is demonstrated how the relative strength of dispersion and diffraction, the strength...
physics
10,101
Power Switching in Hybrid Coherent Couplers
physics.optics
We report on a theoretical and numerical investigation of the switching of power in new hybrid models of nonlinear coherent couplers consisting of optical slab waveguides with various orders of nonlinearity. The first model consists of two guides with second-order instead of the usual third-order susceptibilities as ty...
physics
10,102
Stokes Parameters as a Minkowskian Four-vector
physics.optics
It is noted that the Jones-matrix formalism for polarization optics is a six-parameter two-by-two representation of the Lorentz group. It is shown that the four independent Stokes parameters form a Minkowskian four-vector, just like the energy-momentum four-vector in special relativity. The optical filters are represen...
physics
10,103
A Numerical Study of Absorption by Multilayered Biperiodic Structures
physics.optics
We study the electromagnetic scattering by multilayered biperiodic aggregates of dielectric layers and gratings of conducting plates. We show that the characteristic lengths of such structures provide a good control of absorption bands. The influence of the physical parameters of the problem (sizes, impedances) is disc...
physics
10,104
Propagation of a short laser pulse in a plasma
physics.optics
The propagation of an electromagnetic pulse in a plasma is studied for pulse durations that are comparable to the plasma period. When the carrier frequency of the incident pulse is much higher than the plasma frequency, the pulse propagates without distortion at its group speed. When the carrier frequency is comparable...
physics
10,105
Space-Time Approach to Scattering from Many Body Systems
physics.optics
We present scattering from many body systems in a new light. In place of the usual van Hove treatment, (applicable to a wide range of scattering processes using both photons and massive particles) based on plane waves, we calculate the scattering amplitude as a space-time integral over the scattering sample for an inci...
physics
10,106
On Localized "X-shaped" Superluminal Solutions to Maxwell Equations
physics.optics
In this paper we extend for the case of Maxwell equations the "X-shaped" solutions previously found in the case of scalar (e.g., acoustic) wave equations. Such solutions are localized in theory, i.e., diffraction-free and particle-like (wavelets), in that they maintain their shape as they propagate. In the electromagne...
physics
10,107
Scattering Integral Equations for Diffusive Waves. Detection of Objects Buried in Diffusive Media in the Presence of Interfaces
physics.optics
This paper has been withdrawn by the authors until some changes are made.
physics
10,108
Thirring Solitons in the presence of dispersion
physics.optics
The effect of dispersion or diffraction on zero-velocity solitons is studied for the generalized massive Thirring model describing a nonlinear optical fiber with grating or parallel-coupled planar waveguides with misaligned axes. The Thirring solitons existing at zero dispersion/diffraction are shown numerically to be ...
physics
10,109
Giant phase-conjugate reflection with a normal mirror in front of an optical phase-conjugator
physics.optics
We theoretically study reflection of light by a phase-conjugating mirror preceded by a partially reflecting normal mirror. The presence of a suitably chosen normal mirror in front of the phase conjugator is found to greatly enhance the total phase-conjugate reflected power, even up to an order of magnitude. Required co...
physics
10,110
A simple method for the determination of slowly varying refractive index profiles from in situ spectrophotometric measurements
physics.optics
Reliable control of the deposition process of optical films and coatings frequently requires monitoring of the refractive index profile throughout the layer. In the present work a simple in situ approach is proposed which uses a WKBJ matrix representation of the optical transfer function of a single thin film on a subs...
physics
10,111
What is the velocity of the electromagnetic field?
physics.optics
A new definition for the electromagnetic field velocity is proposed. The velocity depends on the physical fields.
physics
10,112
Visible light emitting devices with Schottky contacts on silicon nanocrystals
physics.optics
We have fabricated light emitting diodes (LEDs) with Schottky contacts on Si-nanocrystals formed by simple techniques as used for standard Si devices. Orange electroluminescence (EL) from these LEDs could be seen with the naked eye at room temperature when a reverse bias voltage was applied. The EL spectrum has a major...
physics
10,113
Optical microsphere resonators: optimal coupling to high-Q whispering gallery modes
physics.optics
A general model is presented for coupling of high-$Q$ whispering-gallery modes in optical microsphere resonators with coupler devices possessing discrete and continuous spectrum of propagating modes. By contrast to conventional high-Q optical cavities, in microspheres independence of high intrinsic quality-factor and c...
physics
10,114
DC-electric-field-induced and low-frequency electromodulation second-harmonic generation spectroscopy of Si(001)-SiO$_2$ interfaces
physics.optics
The mechanism of DC-Electric-Field-Induced Second-Harmonic (EFISH) generation at weakly nonlinear buried Si(001)-SiO$_2$ interfaces is studied experimentally in planar Si(001)-SiO$_2$-Cr MOS structures by optical second-harmonic generation (SHG) spectroscopy with a tunable Ti:sapphire femtosecond laser. The spectral de...
physics
10,115
Nonlinear phase shift without cascaded second-order processes and third order nonlinearity
physics.optics
The new mechanism for obtaining a nonlinear phase shift has been proposed and the schemes are described for its implementation. As it is shown, the interference of two waves with intensity-dependent amplitude ratio coming from the second harmonic generation should produce the nonlinear phase shift. The sign and amount ...
physics
10,116
Full-vector analysis of a realistic photonic crystal fiber
physics.optics
We analyze the guiding problem in a realistic photonic crystal fiber using a novel full-vector modal technique, a biorthogonal modal method based on the nonselfadjoint character of the electromagnetic propagation in a fiber. Dispersion curves of guided modes for different fiber structural parameters are calculated alon...
physics
10,117
Numerical simulation of gliding reflection of X-ray beam from rough surface
physics.optics
A new method for investigation of x-ray propagation in a rough narrow dielectric waveguide is proposed on the basis of the numerical integration of the quazioptical equation. In calculations a model rough surface was used with the given statistical properties. It was shown that the losses in the narrow waveguides stron...
physics
10,118
Quantum Noise Reduction and Generalized Two-Mode Squeezing in a Cavity Raman Laser
physics.optics
We study a generalized notion of two-mode squeezing for the Stokes and anti-Stokes fields in a model of a cavity Raman laser, which leads to a significant reduction in decoherence or quantum noise. The model comprises a loss-less cavity with classical pump, unsaturated medium and arbitrary homogeneous broadening and di...
physics
10,119
Dispersion-induced generation of higher order transversal modes in singly-resonant optical parametric oscillators
physics.optics
We study the effects of higher order transversal modes in a model of a singly-resonant OPO, using both numerical solutions and mode expansions including up to two radial modes. The numerical and two-mode solutions predict lower threshold and higher conversion than the single-mode solution at negative dispersion. Relati...
physics
10,120
Diffractive effects in singly-resonant continuous-wave parametric oscillators
physics.optics
This paper presents a detailed numerical study of the effect of focusing on the conversion efficiency of low-loss singly-resonant parametric oscillators with collinear focusing of pump and signal. Results are given for the maximal pump depletion and for pump power levels required for various amounts of depletion, as fu...
physics
10,121
Optimal conditions for light pulses coherence transformation in thin nonlinear media
physics.optics
Via solution of appropriate variational problem it is shown that light beams with Gaussian spatial profile and sufficiently short duration provide maximal destruction of global coherence under nonlinear self-modulation.
physics
10,122
Dynamics of Fabry-Perot resonators with suspended mirrors. I. Nonlinear coupled oscillators
physics.optics
The dynamics of Fabry-Perot cavity with suspended mirrors is described. The suspended mirrors are nonlinear oscillators interacting with each other through the laser circulating in the cavity. The degrees of freedom decouple in normal coordinates, which are the position of the center of mass and the length of the cavit...
physics
10,123
Self-trapping of Necklace beams in Self-focusing Kerr media
physics.optics
We show that an azimuthally-periodically-modulated bright ring "necklace" beam can self-trap in self-focusing Kerr media and can exhibit stable propagation for very large distances. These are the first bright (2+1) D beams to exhibit stable self-trapping in a system described by the cubic (2+1) D Nonlinear Schrodinger ...
physics
10,124
Zeolite-dye micro lasers
physics.optics
We present a new class of micro lasers based on nanoporous molecular sieve host-guest systems. Organic dye guest molecules of 1-Ethyl-4-(4-(p-Dimethylaminophenyl)-1,3-butadienyl)-pyridinium Perchlorat were inserted into the 0.73-nm-wide channel pores of a zeolite AlPO$_4$-5 host. The zeolitic micro crystal compounds wh...
physics
10,125
Photonic quantum ring laser
physics.optics
We report a quantum ring-like toroidal cavity naturally formed in a vertical-cavity-like active microdisk plane due to Rayleigh's band of whispering gallery modes. The $\sqrt{T}$-dependent redshift and a square-law property of microampere-range threshold currents down to 2 $\mu$A are consistent with a photonic quantum ...
physics
10,126
Wave channeling of X-rays in narrow rough capillaries - non Andronov-Leontovich theory
physics.optics
The effect of capture of X-ray beam into narrow submicron capillary was investigated with account for diffraction and decay of coherency by roughness scattering in transitional boundary layer. In contrast to well-known Andronov-Leontovich approach the losses do not vanish at zero gliding angle and scale proportional to...
physics
10,127
On The Measurement of Photon Flux in Parametric Down Conversion
physics.optics
We report the measurement of the photons flux produced in parametric down-conversion, performed in photon counting regime with actively quenched silicon avalanche photodiodes as single photon detectors. Measurements are done with the detector in a well defined geometrical and spectral situation. By comparison of the ex...
physics
10,128
The dispersion equation for a wave number of the electromagnetic wave in a random medium of the parallel dielectric cylinders
physics.optics
In a frame of quasi-crystal approximation the dispersion equations are obtained for the wave vector of a coherent electromagnetic wave propagating in a media which contains a random set of parallel dielectric cylinders with possible overlapping. The results are compared with that for the case when a regularity at the c...
physics
10,129
Surface and internal scattering in microspheres: limits imposed on the Q-factor and mode splitting
physics.optics
Accurate calculation of internal and surface scattering losses in fused silica microspheres is done. We show that in microspheres internal scattering is partly inhibited as compared to losses in the bulk material. We pay attention on the effect of frozen thermodynamical capillary waves on surface roughness. We calculat...
physics
10,130
Verification of a localization criterion for several disordered media
physics.optics
We analytically compute a localization criterion in double scattering approximation for a set of dielectric spheres or perfectly conducting disks uniformly distributed in a spatial volume which can be either spherical or layered. For every disordered medium, we numerically investigate a localization criterion, and exam...
physics
10,131
Interferometry of hyper-Rayleigh scattering by inhomogeneous thin films
physics.optics
The use of specific symmetry properties of the optical second-harmonic generation (the s,s-exclusion rule) has allowed us to observe high-contrast hyper-Rayleigh interference patterns in a completely diffuse light - an effect having no analog in case of linear (Rayleigh) scattering.
physics
10,132
Self-Pulsating Semiconductor Lasers: Theory and Experiment
physics.optics
We report detailed measurements of the pump-current dependency of the self-pulsating frequency of semiconductor CD lasers. A distinct kink in this dependence is found and explained using rate-equation model. The kink denotes a transition between a region where the self-pulsations are weakly sustained relaxation oscilla...
physics
10,133
Lasing on the D_2 line of sodium in helium atmosphere due to optical pumping on the D_1 line (up-conversion)
physics.optics
A new method is proposed to produce population inversion on transitions involving the ground state of atoms. The method is realized experimentally with sodium atoms. Lasing at the frequency corresponding to the sodium D_2 line is achieved in the presence of pump radiation resonant to the D_1 line with helium as a buffe...
physics
10,134
Optics of Nonuniformly Moving Media
physics.optics
A moving dielectric appears to light as an effective gravitational field. At low flow velocities the dielectric acts on light in the same way as a magnetic field acts on a charged matter wave. We develop in detail the geometrical optics of moving dispersionless media. We derive a Hamiltonian and a Lagrangian to describ...
physics
10,135
Observation of Nonlinear Mode in a Cylindrical Fabry-Perot Cavity
physics.optics
We report 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 chi3 optical nonlinearity due to resonantly-excited Rb-85 vapor, allows the nonlinear mode to form at low incident optical powers of less than a milliwatt. T...
physics
10,136
Optical second harmonic generation probe of two-dimensional ferroelectricity
physics.optics
Optical second harmonic generation (SHG) is used as a noninvasive probe of two-dimensional (2D) ferroelectricity in Langmuir-Blodgett (LB) films of copolymer vinylidene fluoride with trifluorethylene. The surface 2D ferroelectric-paraelectric phase transition in the topmost layer of LB films and a thickness independent...
physics
10,137
All Optical Flip-Flop Based on Coupled Laser Diodes
physics.optics
An all optical set-reset flip flop is presented that is based on two coupled identical laser diodes. The lasers are coupled so that when one of the lasers lases it quenches lasing in the other laser. The state of the flip flop is determined by which laser is currently lasing. Rate equations are used to model the flip f...
physics
10,138
HeXLN: A 2-Dimensional nonlinear photonic crystal
physics.optics
We report on the fabrication of what we believe is the first example of a two dimensional nonlinear periodic crystal\cite{berger}, where the refractive index is constant but in which the 2nd order nonlinear susceptibility is spatially periodic. Such a crystal allows for efficient quasi-phase matched 2nd harmonic genera...
physics
10,139
Effect of laser polarization in laser-assisted electron-helium inelastic collisions:a sturmian approach
physics.optics
The influence of linearly and circularly polarized laser fields on the dynamics of fast electron-impact excitation in atomic helium is discussed. A detailed analysis is made in the excitation of 2^1S, 3^1S and 3^1D dressed states of helium target.
physics
10,140
Theoretical Study of Quantum Dissipation and Laser Noise Effects on the Atomic Response
physics.optics
The nonlinear dynamics of dissipative quantum systems in incoherent laser fields is studied in the framework of master equation with random model describing the laser noise and Markovian approximation for dealing with the system-bath couplings.
physics
10,141
The Kinetic of the Atomic Relaxation Induced by Laser Noise
physics.optics
We present a theoretical study of strong laser-atom interactions, when the laser field parameters are subjected to random processes. The atom is modelled by a two-level and three-level systems, while the statistical fluctuations of the laser field are described by a pre-Gaussian model.
physics
10,142
Polarized Electromagnetic Radiation from Spatially Correlated Sources
physics.optics
We consider the effect of spatial correlations on sources of polarized electromagnetic radiation. The sources, assumed to be monochromatic, are constructed out of dipoles aligned along a line such that their orientation is correlated with their position. In one representative example, the dipole orientations are prescr...
physics
10,143
Hierarchy of time scales and quasitrapping in the N-atom micromaser
physics.optics
We study the dynamics of the reduced density matrix(RDM) of the field in the micromaser. The resonator is pumped by N-atomic clusters of two-level atoms. At each given instant there is only one cluster in the cavity. We find the conditions of the independent evolution of the matrix elements of RDM belonging to a (sub)d...
physics
10,144
Dynamics of Atom-Mediated Photon-Photon Scattering II: Experiment
physics.optics
Temporal and angular correlations in atom-mediated photon-photon scattering are measured. Good agreement is found with the theory presented in Part~I.
physics
10,145
Dynamics of Atom-Mediated Photon-Photon Scattering I: Theory
physics.optics
The mediated photon-photon interaction due to the resonant Kerr nonlinearity in an inhomogeneously broadened atomic vapor is considered. The time-scale for photon-photon scattering is computed and found to be determined by the inhomogeneous broadening and the magnitude of the momentum transfer. This time can be shorter...
physics
10,146
Interfering with Interference: a Pancharatnam Phase Polarimeter
physics.optics
A simple variation of the traditional Young's double slit experiment can demonstrate several subtleties of interference with polarized light, including Berry and Pancharatnam's phase. Since the position of the fringes depends on the polarization state of the light at the input, the apparatus can also be used to measure...
physics
10,147
Soliton electro-optic effects in paraelectrics
physics.optics
The combination of charge separation induced by the formation of a single photorefractive screening soliton and an applied external bias field in a paraelectric is shown to lead to a family of useful electro-optic guiding patterns and properties.
physics
10,148
Femtosecond soliton amplification in nonlinear dispersive traps and soliton dispersion management
physics.optics
The nonlinear pulse propagation in an optical fibers with varying parameters is investigated. The capture of moving in the frequency domain femtosecond colored soliton by a dispersive trap formed in an amplifying fiber makes it possible to accumulate an additional energy and to reduce significantly the soliton pulse du...
physics
10,149
Jaynes-Cummings model with degenerate atomic levels
physics.optics
The Jaynes-Cummings model describing the interaction of a single linearly- polarized mode of the quantized electromagnetic field with an isolated two- level atom is generalized to the case of atomic levels degenerate in the projections of the angular momenta on the quantization axis, which is a usual case in the experi...
physics
10,150
Axicon Gaussian Laser Beams
physics.optics
We deduce the simplest form for an axicon Gaussian laser beam, i.e., one with radial polarization of the electric field.
physics
10,151
Diffraction as a Consequence of Faraday's Law
physics.optics
We consider a linearly polarized electromagnetic wave incident on an opaque screen with square aperture of edge a. An application of Faraday's law to a loop parallel to the screen, on the side away from the source, shows that the wave must have longitudinal components there. The ratio of the longitudinal to transverse ...
physics
10,152
Time-Reversed Diffraction
physics.optics
We show that a time-reversed formulation of Huygens-Kirchhoff diffraction can be used to deduce the transverse and longitudinal fields of a Gaussian laser beam, starting from a simple assumption of a Gaussian beam profile in the far field. An attempt to apply this technique to the far fields of a Hertzian dipole shows ...
physics
10,153
Ultrahigh sensitivity of slow-light gyroscope
physics.optics
Slow light generated by Electromagnetically Induced Transparency is extremely susceptible with respect to Doppler detuning. Consequently, slow-light gyroscopes should have ultrahigh sensitivity.
physics
10,154
Second-harmonic interferometric spectroscopy of the buried Si(111)-SiO$_2$ interface
physics.optics
The second-harmonic interferometric spectroscopy (SHIS) which combines both amplitude (intensity) and phase spectra of the second-harmonic (SH) radiation is proposed as a new spectroscopic technique being sensitive to the type of critical points (CP's) of combined density of states at semiconductor surfaces. The increa...
physics
10,155
Frequency stabilization of a monolithic Nd:YAG ring laser by controlling the power of the laser-diode pump source
physics.optics
The frequency of a 700mW monolithic non-planar Nd:YAG ring laser (NPRO) depends with a large coupling coefficient (some MHz/mW) on the power of its laser-diode pump source. Using this effect we demonstrate the frequency stabilization of an NPRO to a frequency reference by feeding back to the current of its pump diodes....
physics
10,156
Polarization Dependence of Emissivity
physics.optics
We deduce the emissivity of radiation from a metallic surface as a function of angle and polarization. This effect has found application in the calibration of detectors for cosmic microwave background radiation.
physics
10,157
Modulation Instability and Pattern Formation in Spatially Incoherent Light Beams
physics.optics
We present the first experimental observation of modulation instability of partially spatially incoherent light beams in non-instantaneous nonlinear media. We show that even in such a nonlinear partially coherent system (of weakly-correlated particles) patterns can form spontaneously. Incoherent MI occurs above a speci...
physics
10,158
Spectral Dependence of Polarized Radiation due to Spatial Correlations
physics.optics
We study the polarization of light emitted by spatially correlated sources. We show that in general polarization acquires nontrivial spectral dependence due to spatial correlations. The spectral dependence is found to be absent only for a special class of sources where the correlation length scales as the wavelength of...
physics
10,159
Stable oscillating nonlinear beams in square-wave-biased-photorefractives
physics.optics
We demonstrate experimentally that in a centrosymmetric paraelectric non-stationary boundary conditions can dynamically halt the intrinsic instability of quasi-steady-state photorefractive self-trapping, driving beam evolution into a stable oscillating two-soliton-state configuration.
physics
10,160
Comment on "Observation of Superluminal Behaviors in Wave Propagation"
physics.optics
Mugnai et al. have reported an experiment in which microwave packets appear to travel in air with a speed substantially greater than c. They calculate the group velocity of their packets and find that it agrees with their experimental result. That calculation is incorrect. A correct calculation gives a group velocity l...
physics
10,161
Bessel Beams
physics.optics
Scalar Bessel beams are derived both via the wave equation and via diffraction theory. While such beams have a group velocity that exceeds the speed of light, this is a manifestation of the "scissors paradox" of special relativty. The signal velocity of a modulated Bessel beam is less than the speed of light. Forms of ...
physics
10,162
Symmetries of Optical Phase Conjugation
physics.optics
Various algebraic structures of degenerate four-wave mixing equations of optical phase conjugation are analyzed. Two approaches (the spinorial and the Lax-pair based), complementary to each other, are utilized for a systematic derivation of conserved quantities. Symmetry groups of both the equations and the conserved q...
physics
10,163
Extinction theorem for ultrafast pulses
physics.optics
Instead of using frequency dependent refractive index, we propose to use the extinction theorem to describe reflection and transmission of an ultrashort pulse passing through the boundary. When the duration of the pulse is comparable with the relaxation time, the results differ significantly from those given by the tra...
physics
10,164
Polarization Elements-A Group Theoretical Study
physics.optics
The Classification of Polarization elements, the polarization affecting optical devices which have a Jones matrix representation, according to the types of eigenvectors they possess, is given a new visit through the Group-theoretical connection of polarization elements. The diattenuators and retarders are recognized as...
physics
10,165
Strong Discontinuities in the Complex Photonic Band Structure of Transmission Metallic Gratings
physics.optics
Complex photonic band structures (CPBS) of transmission metallic gratings with rectangular slits are shown to exhibit strong discontinuities that are not evidenced in the usual energetic band structures. These discontinuities are located on Wood's anomalies and reveal unambiguously two different types of resonances, wh...
physics
10,166
Slow light
physics.optics
We present a brief classical discussion of a process to reduce the group velocity of an electromagnetic pulse by many orders of magnitude.
physics
10,167
A Variational Approach in the Dissipative Nonlinear Schrödinger Equation
physics.optics
The properties of pulse propagation in a nonlinear fiber including linear damped term added in the usual nonlinear Schr\"odinger equation is analyzed analytically. We apply variational modified approach based on the lagrangian that describe the dynamic of system and with a trial function we obtain a solution which is m...
physics
10,168
Negative Group Velocity
physics.optics
The group velocity for pulses in an optical medium can be negative at frequencies between those of a pair of laser-pumped spectral lines. The gain medium then can amplify the leading edge of a pulse resulting in a time advance of the pulse when it exits the medium, as has been recently demonstrated in the laboratory. T...
physics
10,169
Possibility of a Light Pulse with Speed Greater than c
physics.optics
In two models it is shown that a light pulse propagates from a vacuum into certain media with velocity greater than that of a light in a vacuum (c). By numerical calculation the propagating properties of such a light are given.
physics
10,170
Theory of sub-10 fs Generation in Kerr-lens Mode-locked Solid-State Lasers with a Coherent Semiconductor Absorber
physics.optics
The results of the study of ultra-short pulse generation in continuous-wave Kerr-lens mode-locked (KLM) solid-state lasers with semiconductor saturable absorbers are presented. The issues of extremely short pulse generation are addressed in the frames of the theory that accounts for the coherent nature of the absorber-...
physics
10,171
Soliton Generation and Picosecond Collapse in Solid-State Lasers with Semiconductor Saturable Absorber
physics.optics
Based on self - consistent field theory we study a soliton generation in cw solid-state lasers with semiconductor saturable absorber. Various soliton destabilizations, i.e. the switch from femtosecond to picosecond generation (''picosecond collapse''), an automodulation regime, breakdown of soliton generation and hyste...
physics
10,172
On the sensitivity of wave channeling of X-ray beam to the shape of interface channels
physics.optics
The effect of transmission of x-ray beams through submicron capillaries was investigated with account for diffraction and roughness scattering. Possible explanation of anomalous energy dependence of transmission through thin Cr/C/Cr channeles was given due to effect of periodic deformations.
physics
10,173
Automodulations in Kerr-lens Modelocked Solid-State Lasers
physics.optics
Nonstationary pulse regimes associated with self modulation of a Kerr-lens modelocked Ti:sapphire laser have been studied experimentally and theoretically. Such laser regimes occur at an intracavity group delay dispersion that is smaller or larger than what is required for stable modelocking and exhibit modulation in p...
physics
10,174
Investigation of the Kerr-lens Mode Locking Ability of Cr:ZnSe Solid-State Laser
physics.optics
The theoretical calculation for nonlinear refractive index in Cr: ZnSe - active medium predicts the strong defocusing cascaded second-order nonlinearity within 2000 - 3000 nm spectral range. On the basis of this result the optimal cavity configuration for Kerr-lens mode locking is proposed that allows to achieve a sub-...
physics
10,175
Nonlinear Effects in CW Mode-Locked Solid-State Lasers with Semiconductor Saturable Absorbers
physics.optics
The influence of nonlinear properties of semiconductor saturable absorbers on ultrashort pulse generation was investigated. It was shown, that linewidth enhancement, quadratic and linear ac Stark effect contribute essentially to the mode locking in cw solid-state lasers, that can increase the pulse stability, decrease ...
physics
10,176
Large Coherence Area Thin-Film Photonic Stop-Band Lasers
physics.optics
We demonstrate that the shift of the stop band position with increasing oblique angle in periodic structures results in a wide transverse exponential field distribution corresponding to strong angular confinement of the radiation. The beam expansion follows an effective diffusive equation depending only upon the spectr...
physics
10,177
Phase-coherent frequency measurement of the Ca intercombination line at 657 nm with a Kerr-lens mode-locked femtosecond laser
physics.optics
The frequency of the Calcium ^3P_1--^1S_0 intercombination line at 657 nm is phase-coherently measured in terms of the output of a primary cesium frequency standard using an optical frequency comb generator comprising a sub-10 fs Kerr-lens mode-locked Ti:Sapphire laser and an external microstructure fiber for self-phas...
physics
10,178
A phase-locked frequency divide-by-3 optical parametric oscillator
physics.optics
Accurate phase-locked 3:1 division of an optical frequency was achieved, by using a continuous-wave (cw) doubly resonant optical parametric oscillator. A fractional frequency stability of 2*10^(-17) of the division process has been achieved for 100s integration time. The technique developed in this work can be generali...
physics
10,179
Electromagnetic oscillations in periodic mediums outside the passbands
physics.optics
It was usually assumed that the resonator based on a waveguide has the eigen oscillations that are formed by interference of two waves which propagate in different directions and have equal amplitudes. These patterns are usually called standing waves. We have shown that the eigen oscillations of a resonator which is fi...
physics
10,180
Theory of self phase-locked optical parametric oscillators
physics.optics
The plane-wave dynamics of 3*omega => (2*omega, omega) subharmonic optical parametric oscillators containing a second harmonic generator of the idler wave omega is analyzed analytically by using the meanfield approximation and numerically by taking into account the field propagation inside the media. The resonant Chi(2...
physics
10,181
Mach-Zehnder interferometer based all optical flip-flop
physics.optics
For the first time an all optical flip-flop is demonstrated based on two coupled Mach-Zehnder interferometers which contain semiconductor optical amplifiers in their arms. The flip-flop operation is discussed and it is demonstrated using commercially available fiber pigtailed devices. Being based on Mach-Zehnder interf...
physics
10,182
Anisotropic charge displacement supporting isolated photorefractive optical needles
physics.optics
The strong asymmetry in charge distribution supporting a single non-interacting spatial needle soliton in a paraelectric photorefractive is directly observed by means of electroholographic readout. Whereas in trapping conditions a quasi-circular wave is supported, the underlying double-dipolar structure can be made to ...
physics
10,183
Parametric Processes in a Strong-Coupling Planar Microcavity
physics.optics
I present a theoretical treatment of parametric scattering in strong coupling semiconductor microcavities to model experiments in which parametric oscillator behaviour has been observed. The model consists of a non-linear excitonic oscillator coupled to a cavity mode which is driven by the external fields, and predicts...
physics
10,184
Spectral Characteristics of Ultrashort Pulses in Kerr-lens Mode-Locked Lasers
physics.optics
A number of factors that influence spectral position of the femtosecond pulse in a Kerr-lens modelocked Cr:LiSGaF laser have been identified: high-order dispersion, gain saturation, reabsorption from the ground state, and stimulated Raman scattering. Using the one-dimensional numerical model for the simulation of the l...
physics
10,185
On the origin of the optical nonlinearity of a gallium-silica interface
physics.optics
Simultaneous measurements of the intensity and phase of a probe wave reflected from an interface between silica and elemental alpha-gallium reveal its very strong optical nonlinearity, affecting both these parameters of the reflected wave. The data corroborate with a non-thermal mechanism of optical response which assu...
physics
10,186
Signal velocity, causality, and quantum noise in superluminal light pulse propagation
physics.optics
We consider pulse propagation in a linear anomalously dispersive medium where the group velocity exceeds the speed of light in vacuum (c) or even becomes negative. A signal velocity is defined operationally based on the optical signal-to-noise ratio, and is computed for cases appropriate to the recent experiment where ...
physics
10,187
Polarization dynamics of femtosecond pulses propagating in air
physics.optics
Polarization dynamics of femtosecond light pulses propagating in air is studied by computer simulation. A rich variety of dynamics is found that depends on the initial polarization state and power of the pulse. Effects of polarization on the plasma and supercontinuum generation are also discussed.
physics
10,188
Two-photon absorption in potassium niobate
physics.optics
We report measurements of thermal self-locking of a Fabry-Perot cavity containing a potassium niobate (KNbO3) crystal. We develop a method to determine linear and nonlinear optical absorption coefficients in intracavity crystals by detailed analysis of the transmission lineshapes. These lineshapes are typical of optica...
physics
10,189
Analysis of Optical Pulse Propagation with ABCD Matrices
physics.optics
We review and extend the analogies between Gaussian pulse propagation and Gaussian beam diffraction. In addition to the well-known parallels between pulse dispersion in optical fiber and CW beam diffraction in free space, we review temporal lenses as a way to describe nonlinearities in the propagation equations, and th...
physics
10,190
Absolute frequency measurement of the 171Yb+ clock transition with a Kerr-lens mode-locked femtosecond laser
physics.optics
We have measured the frequency of the $6s^2S_{1/2} - 5d^2D_{3/2}$ electric-quadrupole transition of $^{171}$Yb$^+$ with a relative uncertainty of $1\times 10^{-14}$, $\nu_{Yb}$ = 688 358 979 309 312 Hz $\pm$ 6 Hz. A femtosecond frequency comb generator was used to phase-coherently link the optical frequency derived fro...
physics
10,191
Nonlocal reflection by photonic barriers
physics.optics
The time behaviour of microwaves undergoing partial reflection by photonic barriers was measured in the time and in the frequency domain. It was observed that unlike the duration of partial reflection by dielectric layers, the measured reflection duration of barriers is independent of their length. The experimental res...
physics
10,192
Conditions for Soliton-Like Wave Propagation in Pockels and Photorefractive Media
physics.optics
We study the conditions for soliton-like wave propagation in the Photorefractive (PR) and electro-optic (i.e., Pockels) material, by using Nonlinear Schrodinger (NLS) equation. The complete NLS equation is solved analytically and numerically by transforming it into the phase space. Our results clearly show the existenc...
physics
10,193
Bifurcation of gap solitons through catastrophe theory
physics.optics
In the theory of optical gap solitons, slowly-moving finite-amplitude Lorentzian solutions are found to mediate the transition from bright to coexistent dark-antidark solitary wave pairs when the laser frequency is detuned out of the proper edge of a dynamical photonic bandgap. Catastrophe theory is applied to give a g...
physics
10,194
Direct Determination of Harmonic and Inter-modulation distortions with an application to Single Mode Laser Diodes
physics.optics
Harmonic and Intermodulation distortions occur when a physical system is excited with a single or several frequencies and when the relationship between the input and output is non-linear. Working with non-linearities in the Frequency domain is not straightforward specially when the relationship between the input and ou...
physics
10,195
Understanding multilayers from a geometrical viewpoint
physics.optics
We reelaborate on the basic properties of lossless multilayers. We show that the transfer matrices for these multilayers have essentially the same algebraic properties as the Lorentz group SO(2,1) in a (2+1)-dimensional spacetime, as well as the group SL(2,R) underlying the structure of the ABCD law in geometrical opti...
physics
10,196
Electromagnetic diffraction by a circular cylinder with longitudinal slots
physics.optics
A method is presented to investigate diffraction of an electromagnetic plane wave by an infinitely thin infinitely conducting circular cylinder with longitudinal slots. It is based on the use of the combined boundary conditions method that consists on expressing the continuity of the tangential components of both the e...
physics
10,197
High-resolution Doppler-free molecular spectroscopy with a continuous-wave optical parametric oscillator
physics.optics
We present a reliable, narrow linewidth (100 kHz) continuous-wave optical parametric oscillator (OPO) suitable for high-resolution spectroscopy applications. The OPO is based on a periodically-poled lithium-niobate crystal and features a specially designed intracavity etalon which permits its continuous tuning and stab...
physics
10,198
Fresnel coefficients as hyperbolic rotations
physics.optics
We describe the action of a plane interface between two semi-infinite media in terms of a transfer matrix. We find a remarkably simple factorization of this matrix, which enables us to express the Fresnel coefficients as a hyperbolic rotation.
physics
10,199
Static and Dynamic Regimes of Arbitrary Gain Compensation Single-Mode Laser Diodes
physics.optics
We report on a methodology for the evaluation of the DC characteristics, small-signal frequency response and large-signal dynamic response of carrier and photon density responses in semiconductor laser diodes. A single mode laser is considered and described with a pair of rate equations containing a novel non-linear ga...
physics