Showing papers in "Optics Letters in 1983"
TL;DR: Both the quantum and the excess noise of the local oscillator can be eliminated by coherent subtraction of the two outputs of a 50-50 beam splitter, demonstrating the fact that the basic quantum noise in homodyning and heterodyning is signal quantum fluctuation, not local-oscillator shot noise.
Abstract: Quantum-mechanical calculations of the mean-square fluctuation spectra in optical homodyning and heterodyning are made for arbitrary input and local-oscillator quantum states. In addition to the unavoidable quantum fluctuations, it is shown that excess noise from the local oscillator always affects homodyning and, when it is broadband, also heterodyning. Both the quantum and the excess noise of the local oscillator can be eliminated by coherent subtraction of the two outputs of a 50-50 beam splitter. This result also demonstrates the fact that the basic quantum noise in homodyning and heterodyning is signal quantum fluctuation, not local-oscillator shot noise.
591 citations
TL;DR: It is shown here from the general two-soliton function that solitons in fibers exert forces on their neighbors that decrease exponentially with the distance between them and depend sinusoidally on their relative phase.
Abstract: The propagation of light pulses as solitons in optical fibers may form the basis of a viable means of communication. We show here from the general two-soliton function that solitons in fibers exert forces on their neighbors that decrease exponentially with the distance between them and depend sinusoidally on their relative phase. These forces account for the displacements suffered by solitons during collisions, and their effects must be taken into account in system design.
539 citations
TL;DR: Influences of particle size on surface-enhancement processes are discussed in terms of a simple physical model and the importance of higher-order multipoles is assessed by analyzing their contributions separately.
Abstract: Influences of particle size on surface-enhancement processes are discussed in terms of a simple physical model. When the size of a silver sphere is increased, the magnitude of the enhancement exhibits a slight increase followed by a strong decrease. Simultaneously the plasmon resonance is shifted and severely broadened. To interpret these effects, a self-consistent calculation of the particle polarization is performed. Initial increase in magnitude and shift of the resonance are due to dynamic depolarization, whereas the decrease in magnitude and broadening are caused by radiation damping. The importance of higher-order multipoles is assessed by analyzing their contributions separately.
413 citations
TL;DR: It is shown that the control of the index gradient as a design parameter can significantly enhance the performance of interference coatings.
Abstract: Thin-film gradient-index profiles have been analyzed and new profiles have been synthesized for broadband antireflection coatings on dielectric surfaces. It is shown that the control of the index gradient as a design parameter can significantly enhance the performance of interference coatings.
403 citations
TL;DR: The narrowing of pulses to widths as small as 0.26 psec by various lengths, short relative to the soliton period, of single-mode, low-loss optical fiber is reported to be in at least semiquantitative agreement with prediction based on the nonlinear Schrödinger equation.
Abstract: We report the narrowing of pulses, initially 7 psec FWHM, to widths as small as 0.26 psec by various lengths, short relative to the soliton period, of single-mode, low-loss optical fiber. Since the ~1.5-μm wavelength lies in the region of negative group-velocity dispersion (∂νg/∂λ 10) soliton number. We show these results to be in at least semiquantitative agreement with prediction based on the nonlinear Schrodinger equation.
382 citations
TL;DR: Gigawatt white-light continuum pulses that permit spectroscopic measurements with a time resolution of 80 fsec are obtained that are consistent with self-phase modulation having a prominent role in generation of the continuum.
Abstract: We obtain gigawatt white-light continuum pulses that permit spectroscopic measurements with a time resolution of 80 fsec. These pulses extend continuously from 0.19 to 1.6 μm and have time sweeps as small as 10 fsec/1000 A. We find temporal, spatial, and spectral properties that are consistent with self-phase modulation having a prominent role in generation of the continuum.
379 citations
TL;DR: Calculation of the signal-to-noise density ratio for a homodyne/heterodyne receiver utilizing two detectors show that excess intensity noise in the local oscillator can be canceled and need not degrade the performance of the receiver.
Abstract: Semiclassical calculations of the signal-to-noise density ratio for a homodyne/heterodyne receiver utilizing two detectors are made. These calculations show that excess intensity noise in the local oscillator can be canceled and need not degrade the performance of the receiver. An experimental demonstration of excess-noise cancellation is reported.
263 citations
TL;DR: A passive fiber-optic resonator technique for rotation sensing has been investigated and preliminary data show a noise-equivalent rotation-rate sensitivity of 0.5 degrees /h (tau= 1 sec), which is an order of magnitude above the photonshot-noise limit.
Abstract: A passive fiber-optic resonator technique for rotation sensing has been investigated. Preliminary data show a noise-equivalent rotation-rate sensitivity of 0.5°/h (τ= 1 sec), which is an order of magnitude above the photonshot-noise limit. The major sources of error and ways of reducing such errors are discussed.
215 citations
TL;DR: The exact solution of the scalar-wave equation for a rectangular-core waveguide structure is reported and a perturbation analysis for evaluating accurately the propagation characteristics of practical integrated-optical structures is developed.
Abstract: We report the exact solution of the scalar-wave equation for a rectangular-core waveguide structure and develop a perturbation analysis for evaluating accurately the propagation characteristics of practical integrated-optical structures. We show that the present method gives results that are more accurate than other analytical methods reported earlier.
213 citations
TL;DR: The real-time optical Fourier transformer is shown to be realizable by using dispersive single-mode fibers and chirping lasers.
Abstract: The general concept of temporal Fourier transformation in dispersive media is analyzed. The real-time optical Fourier transformer is shown to be realizable by using dispersive single-mode fibers and chirping lasers.
176 citations
TL;DR: The angular widths of the observed resonance in silver and aluminum films are both reduced by over an order of magnitude relative to that associated with the Kretschmann excited mode.
Abstract: We report the first observation to our knowledge of a sharp minimum in the attenuated total reflectivity of a thin metal film between index-matching layers. The resonance is due to the excitation of the long-range surface-plasmon mode on both sides of the thin metal films, as originally discussed by Sarid [Phys. Rev. Lett. 47, 1927 (1981)]. The angular widths of the observed resonance in silver and aluminum films are both reduced by over an order of magnitude relative to that associated with the Kretschmann excited mode.
TL;DR: It is proved that a small dielectric particle cannot be trapped by using only the scattering force of optical radiation pressure, and the implications of the theorem for recent proposals for the optical trapping of neutral atoms are discussed.
Abstract: We prove an optical radiation Earnshaw theorem: A small dielectric particle cannot be trapped by using only the scattering force of optical radiation pressure. A corollary is that the gradient or dipole force is necessary to any successful optical trap. We discuss the implications of the theorem for recent proposals for the optical trapping of neutral atoms.
TL;DR: A preliminary qualitative kinetic model is proposed to describe the vapor-film interaction in a multiple-reflecting optical waveguide device capable of reversibly sensing ammonia vapors.
Abstract: A small glass capillary tube was fitted with a light-emitting diode and a phototransistor detector to form a multiple-reflecting optical waveguide device. When the capillary was coated with a thin solid film composed of an oxazine perchlorate dye, the device was demonstrated to be capable of reversibly sensing ammonia vapors. Ammonia-vapor concentrations from 1000 parts in 106 (ppm) to less than 60 ppm were easily and reproducibly detected. A preliminary qualitative kinetic model is proposed to describe the vapor–film interaction.
TL;DR: A technique is demonstrated for measuring velocity at multiple locations in a plane of a gaseous flowfield using Doppler-shifted absorption with fluorescence detection from iodine molecules, excited by a sheet of tunable single-axial-mode argon-ion laser radiation.
Abstract: A technique is demonstrated for measuring velocity at multiple locations in a plane of a gaseous flowfield using Doppler-shifted absorption with fluorescence detection from iodine molecules, excited by a sheet of tunable single-axial-mode argon-ion laser radiation at 514.5 nm. Measurements were made simultaneously at 10,000 points in an iodine-seeded supersonic flowfield with a 100 x 100 element photodiode array camera and were found to agree well with a numerical solution for the velocity field. The accuracy with which a component of velocity can be measured is limited, in the current approach, by the iodine linewidth to about +/-5 m/sec.
TL;DR: The efficiency with which a surface polariton at a metal-dielectric interface is excited when a p-polarized volume electromagnetic wave is incident upon the end face of the metal- dielectric system that is normal to the interface is calculated.
Abstract: We calculate the efficiency with which a surface polariton at a metal–dielectric interface is excited when a p-polarized volume electromagnetic wave is incident upon the end face of the metal–dielectric system that is normal to the interface. We find generation efficiencies of approximately 90%.
TL;DR: The absolute frequency of the 473-THz He-Ne laser, stabilized on the g or i hyperfine component of the (127)I(2) 11-5 R(127) transition, was measured by comparing its frequency with a known frequency synthesized by summing the radiation from three lasers in a He- Ne plasma.
Abstract: The absolute frequency of the 473-THz He–Ne laser (633 nm), stabilized on the g or i hyperfine component of the 127I2 11–5 R(127) transition, was measured by comparing its frequency with a known frequency synthesized by summing the radiation from three lasers in a He–Ne plasma. The three lasers were (1) the 88-THz CH4-stabilized He–Ne laser (3.39 μm), (2) a 125-THz color-center laser (2.39 μm) with its frequency referenced to the RII(26) 13C18O2 laser, and (3) the 260-THz He–Ne laser (1.15 μm) referenced to an I2-stabilized dye laser at 520 THz (576nm). The measured frequencies are 473 612 340.492 and 473 612 214.789 MHz for the g and i hyperfine components, respectively, with a total uncertainty of 1.6 parts in 1010. The frequency of the i component adjusted to the operating conditions recommended by the Bureau International des Poids et Mesures is 473 612 214.830 ± 0.074 MHz.
TL;DR: A novel embossing technique for fabricating integrated optical components in hard and resistant inorganic waveguiding materials of good optical quality is described and surface-relief gratings with 1200 lines/mm on SiO( 2)-TiO(2) waveguides are fabricated.
Abstract: We describe a novel embossing technique for fabricating integrated optical components in hard and resistant inorganic waveguiding materials of good optical quality. The desired structure is embossed into a dip-coated deformable gel film prepared from organometallic solutions. Subsequent heat treatment transforms it into inorganic hard oxide material. We have successfully fabricated surface-relief gratings with 1200 lines/mm on SiO2–TiO2 waveguides (with refractive index nF ≃ 1.8, thickness dF ≃ 120 nm, and loss <1 dB/cm). The embossed gratings served as input and output grating couplers and as Bragg reflectors. We propose to fabricate other integrated optical components, for example, channel waveguides, with this method.
TL;DR: By use of the stimulated Raman process, optical solitons can be amplified and reshaped while they propagate through a glass fiber to allow the separation between two repeaters (amplifiers) to be decided by the fiber loss rather than by the Fiber dispersion.
Abstract: By use of the stimulated Raman process, optical solitons can be amplified and reshaped while they propagate through a glass fiber. When an appropriate level is chosen for the pump power (10–100 mW for 10-psec solitons), the solitons can be reshaped adiabatically. The method allows the separation between two repeaters (amplifiers) to be decided by the fiber loss rather than by the fiber dispersion.
TL;DR: Digital applications of speckle masking to close spectroscopic double stars are presented and Diffraction-limited resolution (0.03 arc see) was achieved, which is about 30 times higher than the resolution of conventional astrophotography.
Abstract: Speckle masking is a method for reconstructing high-resolution images of general astronomical objects from stellar speckle interferograms In speckle masking no unresolvable star is required within the isoplanatic patch of the object We present digital applications of speckle masking to close spectroscopic double stars The speckle interferograms were recorded with the European Southern Observatory's 36-m telescope Diffraction-limited resolution (003 arc see) was achieved, which is about 30 times higher than the resolution of conventional astrophotography
TL;DR: It is demonstrated the possibility of controlling, practically independently, the form and indices of proton-exchanged lithium niobate guides by means of guide annealing and proton exchange in lithium-rich solutions.
Abstract: We demonstrate the possibility of controlling, practically independently, the form and indices of proton-exchanged lithium niobate guides by means of guide annealing and proton exchange in lithium-rich solutions. Experimental results are presented that indicate how one can realize specific guide designs.
TL;DR: The propagation and attenuation constants of long-range surface-plasmon polaritons propagating on thin metal films have been measured for several film thicknesses by using a hemispherical retroreflecting coupler in agreement with theoretical dispersion curves.
Abstract: The propagation and attenuation constants of long-range surface-plasmon polaritons propagating on thin metal films have been measured for several film thicknesses by using a hemispherical retroreflecting coupler The results are in agreement with our theoretical dispersion curves, which predict that the attenuation constant of this mode can decrease by a factor of 63 relative to that obtained with a thick metal film
TL;DR: The introduction of a glass prism in a ring dye laser is shown to provide simultaneous wavelength selection and pulse compression.
Abstract: The introduction of a glass prism in a ring dye laser is shown to provide simultaneous wavelength selection and pulse compression.
TL;DR: Pulse restoration occurs despite initial spectral broadening from self-phase modulation and temporal compression as a result of negative group-velocity dispersion acting on the chirped pulse.
Abstract: Restoration in both shape and spectrum of a (train of) 6.4-psec optical pulses has been observed at the soliton period in a single-mode fiber. The source was an F2+ color-center laser at 1.55 μm, and the fiber was 1.3 km long, which was one soliton period for this pulse width and wavelength. As predicted by the nonlinear Schrodinger equation, pulse restoration occurs despite initial spectral broadening from self-phase modulation and temporal compression as a result of negative group-velocity dispersion acting on the chirped pulse.
TL;DR: In this article, an interferometer with a self-pumped phase-conjugating mirror was demonstrated, which eliminates the effects of turbulence or optical distortion in the beam path yet responds to any uniform phase change.
Abstract: An interferometer having a self-pumped phase-conjugating mirror is demonstrated. This device eliminates the effects of turbulence or optical distortion in the beam path yet responds to any uniform phase change.
TL;DR: A novel technique, photoionization-controlled loss spectroscopy, is proposed to eliminate the quenching dependence of the fluorescence signal.
Abstract: We report the first two-photon-excited hydrogen-atom fluorescence measurements in flames made to our knowledge. The n = 3 level of the H atom was excited by 205.1-nm radiation generated by Raman shifting a 224-nm beam produced by frequency mixing. Fluorescence was observed at 656.3 nm as a result of radiative decay from n = 3 to n = 2, the Balmer-α transition. A novel technique, photoionization-controlled loss spectroscopy, is proposed to eliminate the quenching dependence of the fluorescence signal.
TL;DR: The temporal distortion and spectral broadening of a pulse generated by the combined effects of group-velocity dispersion and self-phase modulation is removed by reflection of a cw-pumped, broadband, unityreflecting Kerr-like optical phase conjugator followed by retraversal of the nonlinear medium.
Abstract: We show that the temporal distortion and spectral broadening of a pulse generated by the combined effects of group-velocity dispersion and self-phase modulation is removed by reflection of a cw-pumped, broadband, unity-reflecting Kerr-like optical phase conjugator followed by retraversal of the nonlinear medium We also examine numerically the effects of finite linear loss in the material, of nonunity conjugate reflectivity, and of finite conjugator thickness
TL;DR: A calorimetric technique, photothermal deflection spectroscopy, is employed to monitor the absorption of alpha-SiH(x) films textured by the natural lithography process, and the observed enhancement factors are consistent with full internal phase-space randomization of the incoming light.
Abstract: Complete statistical randomization of the direction of propagation of light trapped in semiconductor films can result in a large absorption enhancement. We have employed a calorimetric technique, photothermal deflection spectroscopy, to monitor the absorption of alpha-SiH(x) films textured by the natural lithography process. The observed enhancement factors, as high as 11.5, are consistent with full internal phase-space randomization of the incoming light.
IBM1
TL;DR: The experimental results agree well with the predicted intensity dependence of the reshaping action of nonlinear birefringence during passage through a 150-cm-long, single-mode optical fiber and a crossed polarizer.
Abstract: We report the observation of strong reshaping of 3-psec dye-laser pulses by nonlinear birefringence during passage through a 150-cm-long, single-mode optical fiber and a crossed polarizer. For lower-intensity input pulses to the fiber, the transmitted pulses were observed to be proportional to the cube of the input pulses. With increased intensity, more-complicated pulse shapes were obtained. Our experimental results agree well with the predicted intensity dependence of the reshaping action.
TL;DR: This work presents a method for reducing subaperture testing data that requires no a priori knowledge of the relative piston and tilt of the subAPertures, and results of applying this method to analyze subaparture testing interferograms are presented.
Abstract: Subaperture testing provides an attractive alternative to large monolithic test optics for evaluation of large optical systems. We present a method for reducing subaperture testing data that requires no a priori knowledge of the relative piston and tilt of the subapertures. Results of applying this method to analyze subaperture testing interferograms are presented. In particular, the behavior of this method in the presence of data noise and for different subaperture configurations is studied.
TL;DR: Surface-plasmon polaritons guided by thin, lossy metallic films bounded by dissimilar dielectric media are investigated, and new solutions to the dispersion relation are found, representing waves that are leaky in one of the dielectrics.
Abstract: Surface-plasmon polaritons guided by thin, lossy metallic films bounded by dissimilar dielectric media are investigated. New solutions to the dispersion relation are found, representing waves that are leaky (radiative) in one of the dielectrics. The new waves are interpreted in terms of the coupling of a damped surface plasmon at one interface with continuum modes at the other. Their excitation by end-fire coupling techniques is suggested.