Showing papers in "Optics Communications in 1994"

TL;DR: In this paper, a spiral phaseplate can convert a TEM00 laser beam into a helical wavefront beam with a phase singularity at its axis, and the diffractive-optical effect of the spiral phase plate is implemented by index matching a macroscopic structure in an optical immersion.

TL;DR: In this article, the simple relationship between total angular momentum and energy and the seemingly natural separation of the angular momentum into spin and orbital components in the paraxial approximation were investigated for a general non-paraxial form of monochromatic beam with near cylindrical symmetry.

TL;DR: In this paper, a simple propagation law is found for light beams of various orders and their field distribution across the waist plane is similar to that produced by an ordinary gaussian beam except that the central region is flattened.

TL;DR: In this paper, it is demonstrated that calculating the T-matrix using extended precision instead of double precision floating-point variables is an effective approach for suppressing the numerical instability in computations for spheroids.

TL;DR: In this paper, high-Q optical whispering-gallery modes TE(TM)lmq in spheroidal dielectric microresonators are shown to be equivalent to precessing circular modes with the rate of precession depending on the value of the residual resonator nonsphericity.

TL;DR: In this article, the gain and index nonlinearities in InGaAsP optical amplifiers operating in the 1.5 μm region of the spectrum were investigated using time domain reflectometry.

TL;DR: In this article, it was shown that a frozen-in space charge field causes the appearance of high quadratic nonlinearities in thermally poled glass by experimental tests of the ratio of nonlinear tensor components and the spatial distribution of the induced chi(2).

TL;DR: In a confocal theta arrangement the axial discrimination is substantially improved over a linear confocal arrangement and the observation volume becomes spherical using a numerical aperture of 094 in water as discussed by the authors.

TL;DR: Very pure optical helices have been generated in an argon ion laser of low Fresnel number as discussed by the authors, with continuous cophasal surface of helical form, clearly demonstrated by spiral interference fringes produced in a novel interferometric arrangement.

TL;DR: In this paper, the generalized Lorenz-Mie theory is used to compute the radiation pressure force components on a particle arbitrarily located in a Gaussian beam, and the influence of the Gaussian character of the beam on resonance structures is discussed.

TL;DR: In this paper, two extended-cavity diode lasers have been optically phase-locked at a frequency offset of 9.192 GHz to stimulate atomic velocity-selective Raman transitions on the 852 nm caesium D 2 line.

TL;DR: In this paper, a β-barium borate (BBO) femtosecond optical parametric oscillator (OPO) pumped by the second-harmonic of a modelocked 82 MHz Ti:sapphire laser is described.

TL;DR: In this article, it was shown that two-photon absorption confines the illumination volume and present quantitative evidence that an additional confocal arrangement of the detector further improves the resolution by 48%.

TL;DR: In this article, an atom moving in a light beam with orbital angular momentum experiences an azimuthal shift in the resonant frequency in addition to the usual axial Doppler and recoil shifts.

TL;DR: In this article, the properties of pulse propagation in a nonlinear fiber including negative fourth order dispersion added to anomalous second-order dispersion are analyzed numerically and analytically.

TL;DR: In this paper, a real-time interferometric measurement of the refractive index as a function of wavelength is presented, which consists in the spectral analysis of the interferogram which is built up when the specimen is placed in a Michelson interferometer illuminated with a broad-continuous spectrum light source.

TL;DR: In this paper, the operating characteristics of a singly-resonant femtosecond optical parametric oscillator (OPO) based on a noncritically phasematched geometry in KTP are described.

TL;DR: Fractional Fourier transforms of an arbitrary degree can be implemented by refractive lenses as mentioned in this paper, and perfect imaging systems and correlators may be implemented using cascading fractional-fractional transformer units of the same family and fractional degree.

TL;DR: In this article, the electromagnetic field transfer from a spherical emitter to a spherical receiver is expressed through a fractional order Fourier transform and the operator composition law applied to fractional transforms is in accordance with Huygens principle.

TL;DR: In this paper, a multilayer structure is realized where a laser beam is coupled to a dielectric waveguide by optical tunnelling through a solid gap, which provides an enhanced evanescent wave in the vacuum above the waveguide, that can be used as an atomic mirror.

TL;DR: In this article, a method for increasing the resolution in far-field fluorescence light microscopy by a factor of 2 was described, where a lateral resolution of 75 nm was achieved with a lens of numerical aperture of 1.4 by a two-photon excitation mode with each photon stemming from displaced focused light beams of λ = 500 nm and overlapping main maxima.

TL;DR: In this paper, the fast Fourier transform beam propagation method (FFT-BPM) was used to describe diffraction of electromagnetic waves and introduced a time-domain version that takes into account arbitrary longitudinal index profiles, as well as transverse effects.

TL;DR: In this article, the first time was reported room temperature cw laser action of a Yb3+, Er3+-doped orthosilicate Y2SiO5 single crystal at about 1.57 μm.

TL;DR: In this article, the shape of the 4 I 13 2 → 4 I 15 2 transition depends on the concentration of Er3 + ions in TiO2 thin films (thickness=80nm).

TL;DR: In this paper, an effective absorption length of 5km was obtained with a high finesse (∼18000) cavity and a diode-laser-pumped Nd: YAG laser.

TL;DR: In this article, a fiber probe with a 100 nm diameter aperture of a photon scanning tunneling microscope (PSTM) was used to realize localized photochemical processes in LB films of photochromic material.

TL;DR: In this article, a common path phase shifting interferometer using a liquid-crystal cell as a phase modulator is proposed, which makes quantitative measurements possible as well as qualitative observations for phase objects like in a Zernike's phase contrast microscope.

TL;DR: In this paper, the implications of dielectric confinement on the linear and nonlinear optical properties of semiconductor-doped glasses in the resonant regime are considered, and it is shown that the problem of self-reaction must be properly taken into account.

TL;DR: In this paper, a three-path optical parametric generator pumped by the second harmonic of the Nd-laser produces tunable near infrared pulses with an energy of up to 25 μJ.

TL;DR: In this paper, the authors investigated stationary soliton-like pulse propagation in nonlinear optical fibres, taking into account the effects of fourth order dispersion, and a new type of stationary stable solitonlike solution was found.