Showing papers on "Optical microcavity published in 1999"
TL;DR: A laser cavity formed from a single defect in a two-dimensional photonic crystal is demonstrated and pulsed lasing action has been observed at a wavelength of 1.5 micrometers from optically pumped devices with a substrate temperature of 143 kelvin.
Abstract: A laser cavity formed from a single defect in a two-dimensional photonic crystal is demonstrated. The optical microcavity consists of a half wavelength–thick waveguide for vertical confinement and a two-dimensional photonic crystal mirror for lateral localization. A defect in the photonic crystal is introduced to trap photons inside a volume of 2.5 cubic half-wavelengths, approximately 0.03 cubic micrometers. The laser is fabricated in the indium gallium arsenic phosphide material system, and optical gain is provided by strained quantum wells designed for a peak emission wavelength of 1.55 micrometers at room temperature. Pulsed lasing action has been observed at a wavelength of 1.5 micrometers from optically pumped devices with a substrate temperature of 143 kelvin.
2,310 citations
26 Jul 1999
TL;DR: In this paper, a new type of optical microcavity using 2D photonic crystals embedded in a half-wavelength thick waveguide was proposed, which enables one to tailor the device for vertical emission or coupling into an in-plane waveguide.
Abstract: We form a new type of optical microcavity using 2D photonic crystals embedded in a half wavelength thick waveguide Modes localized to a single defect in the photonic crystal can be theoretically shown to have small mode volumes The flexibility in design of the photonic crystal enables one to tailor the device for vertical emission or for coupling into an in-plane waveguide The added versatility in being able to etch the laser cavity may also help develop low threshold laser sources in material systems in which high index contrast epitaxial mirrors do not exist
206 citations
TL;DR: In this article, an omnidirectional reflector and a microcavity resonator with resonance at λ =1500 nm and achieved a quality factor of Q=35.
Abstract: Thin films of SiO2 and TiO2 were used to fabricate one-dimensional photonic crystal devices using the sol-gel method: an omnidirectional reflector and microcavity resonator. The reflector consisted of six SiO2/TiO2 bilayers, designed with a stopband in the near infrared. Reflectivity over an incident angle range of 0°–80° showed an omnidirectional band of 70 nm, which agrees with theoretical predictions for this materials system. The microcavity resonator consisted of a TiO2 Fabry–Perot cavity sandwiched between two SiO2/TiO2 mirrors of three bilayers each. We have fabricated a microcavity with resonance at λ=1500 nm and achieved a quality factor of Q=35. We measured a resonance frequency modulation with a change in incident angle of light and defect layer thickness.
158 citations
TL;DR: In this article, the authors presented a general method for the /spl beta/ factor calculation in optical microcavities based on the classical model for atomic transitions in a semiconductor active medium, which is used to evolve the electromagnetic fields of the system and calculate the total radiated energy, as well as the energy radiated into the mode of interest.
Abstract: We present a general method for the /spl beta/ factor calculation in optical microcavities. The analysis is based on the classical model for atomic transitions in a semiconductor active medium. The finite-difference time-domain method is used to evolve the electromagnetic fields of the system and calculate the total radiated energy, as well as the energy radiated into the mode of interest. We analyze the microdisk laser and compare our result with the previous theoretical and experimental analyses. We also calculate the /spl beta/ factor of the microcavity based on a two-dimensional (2-D) photonic crystal in an optically thin dielectric slab. From the /spl beta/ calculations, we are able to estimate the coupling to radiation modes in both the microdisk and the 2-D photonic crystal cavity, thereby showing the effectiveness of the photonic crystal in suppressing in-plane radiation modes.
96 citations
TL;DR: In this article, add-drop filters using racetrack-shaped resonators coupled to straight waveguides across gaps which are larger compared with the conventional microcavity ring resonators are characterized and are determined uniquely by the round-trip loss and the coupling factor of the resonator.
Abstract: We have demonstrated add-drop filters using racetrack-shaped resonators coupled to straight waveguides across gaps which are larger compared with the conventional microcavity ring resonators. The finesse and the maximum transmission are characterized and are shown to be determined uniquely by the round-trip loss and the coupling factor of the resonator.
95 citations
TL;DR: In this paper, a novel setup for investigations in cavity quantum electrodynamics is described, which combines an optical microcavity (finesse 4.3×105) with an atomic 85Rb fountain, allowing full control over density and velocity of atoms entering the optical cavity.
84 citations
TL;DR: In this article, a very small apertured microcavities with quantum-dot light emitters were used to obtain electronic confinement within the aperture, and a 2.3 increase in the averaged spontaneous emission rate was achieved.
Abstract: Spontaneous lifetime control is demonstrated using very small apertured microcavities, with quantum-dot light emitters used to obtain electronic confinement within the aperture. A factor of 2.3 increase in the averaged spontaneous emission rate is achieved due to the optical confinement. The enhancement/inhibition ratio of the spontaneous emission rate tracks the optical mode size and spectral response of the apertured microcavity.
81 citations
TL;DR: In this paper, the authors used a photon scanning tunneling microscope to map whispering gallery modes in cylindrical integrated optics microcavities with a spatial resolution of 50 nm, and observed an unexpectedly rich variety of intracavity phenomena, such as polarization conversion and interference of copropagating and counterpropagating modes, directly observed.
Abstract: Whispering gallery modes in cylindrical integrated optics microcavities have, for what is to our knowledge the first time, been mapped with a photon scanning tunneling microscope. Optical images were obtained with a spatial resolution of 50 nm. By combination of information on the spatial optical distributions with wavelength-dependent measurements, an unexpectedly rich variety of intracavity phenomena, such as polarization conversion and interference of copropagating and counterpropagating modes, could be directly observed. A quantitative comparison of the experimental data with computer simulations results in a comprehensive understanding of the various whispering gallery modes inside the microcavity.
71 citations
TL;DR: In this article, a vertical-cavity surface-emitting laser (VCSEL) with a monolithically integrated diffractive optical element (DOE) was demonstrated for advanced beam shaping.
Abstract: We have demonstrated a vertical-cavity surface-emitting laser (VCSEL) with a monolithically integrated diffractive optical element (DOE) for advanced beam shaping. The DOE is a two-level surface relief, etched into the GaAs substrate beneath a bottom-emitting VCSEL. The combination generates a 4/spl times/4 array of focused spots 10 mm from the substrate with spot sizes down to less than 400 /spl mu/m, almost at the diffraction limit. Diffraction efficiencies of 29% and uniformity errors of 14% were measured.
52 citations
TL;DR: In this article, a selective technique based on etching after electron-beam lithography, combined with the use of an optical microscope to enhance the spatial resolution of a time-resolved photoluminescence system, enabled the observation of single quantum dots.
Abstract: We present time-resolved optical studies of single self-assembled quantum dots. The dots were obtained by Stranski-Krastanow growth of InP on ${\mathrm{Ga}}_{0.5}{\mathrm{In}}_{0.5}\mathrm{P}.$ A selective technique based on etching after electron-beam lithography, combined with the use of an optical microscope to enhance the spatial resolution of a time-resolved photoluminescence system, enabled the observation of single quantum dots. The emission linewidth of a single InP dot is observed to be around 3 meV. The evolution of the time-resolved photoluminescence spectra was studied as a function of excitation intensity. Under intense pulsed excitation the decay is no more a simple exponential due to feeding from higher energy levels, as a result of state filling. A four-level rate equation system is successfully used to model the results.
51 citations
TL;DR: In this article, a data transparent reconfigurable optical interconnection system based on optical injection controlled polarization switching in a master-slave vertical-cavity surface-emitting laser (VCSEL) configuration is demonstrated.
Abstract: We demonstrate a data transparent reconfigurable optical interconnection system based on optical injection controlled polarization switching in a master-slave vertical-cavity surface-emitting laser (VCSEL) configuration. A 140-Mb/s data stream generated by the slave VCSEL is redirected by an anisotropic diffractive optical element depending on the polarization state of the emitted light. The polarization of the slave laser is controlled by injecting an orthogonally polarized optical signal from a master laser. The current modulation of the master VCSEL and the subsequent polarization switching of the slave VCSEL occur at 40 MHz. In our setup, both the data rate and the optical interconnection reconfiguration rate are limited by the electronic drive circuitry and could in principle attain the gigahertz range.
TL;DR: In this paper, the effect of self-adjustment of the cavity mode in vertical cavity surface-emitting lasers containing three-period InGaAs-GaAs vertically-coupled quantum dots has been observed.
Abstract: The effect of self-adjustment of the cavity mode in vertical cavity surface-emitting lasers containing three-period InGaAs-GaAs vertically-coupled quantum dots has been observed. The effect originates from a strong modulation of the refractive index near the gain peak, caused by excitons in quantum dots. The possibility of single quantum dot lasing is demonstrated.
TL;DR: In this article, the spontaneous emission characteristics from apertured microcavities were studied using quantum-dot light emitters, and it was shown that the micro-cavity enhancement can lead to nearly single-mode and high-speed operation even in the spontaneous regime.
Abstract: Spontaneous emission characteristics from apertured microcavities are studied using quantum-dot light emitters. Spatial averaging over the emitter positions within the apertures significantly impacts the measured lifetime changes, but lifetime changes due to the aperture modes are still readily observed. A maximum increase of a factor of /spl sim/2.5 over the cavity-free emission rate is measured. We argue that, for a narrow bandwidth emitter, the microcavity enhancement can lead to nearly-single-mode and high-speed operation even in the spontaneous regime.
TL;DR: In this paper, an active layer based on multiquantum wells has been evaluated by means of a separate-confinement laser diode structure grown on a GaSb substrate by molecular beam epitaxy.
Abstract: Gallium antimonide and related compounds are promising materials for fabricating monolithic vertical cavity semiconductor lasers operating at telecommunications wavelengths. With that aim active layers based on multiquantum wells have been evaluated by means of a separate-confinement laser diode structure grown on a GaSb substrate by molecular beam epitaxy. Owing to optimization of the growing process, for the well/barrier structure, laser emission at 1.4 m has been obtained at 80 K with a threshold current as low as 15 mA for a 640 m long and 15 m wide mesa stripe structure. At room temperature laser emission occurred at 1.55 m with a pulsed threshold current density of 4 kA according to the measured characteristic temperature of 50 K. In a first attempt such an active layer has been included in a 1.5 m microcavity involving antimonide Bragg mirrors.
TL;DR: Combined lateral-vertical oxidation of AlGaAs is investigated as a means of tuning the resonant wavelength of a semiconductor microcavity after the epitaxial growth as mentioned in this paper.
Abstract: Combined lateral-vertical oxidation of AlGaAs is investigated as a means of tuning the resonant wavelength of a semiconductor microcavity after the epitaxial growth. It is shown that this technique can provide arrays with a wavelength spread equal to the cavity's free spectral range with a single postgrowth processing step. Design issues for multiple-wavelength vertical-cavity laser arrays using this postgrowth tuning technique are discussed, comparing the performance of devices with all-semiconductor and partially or totally oxidized Bragg mirrors. Experimental results are presented on arrays with a 48-nm lasing span around 970 nm, using partially and totally oxidized mirrors.
TL;DR: In this paper, the reflectivity of a microcavity filled with a quadratic nonlinear material is shown to be actively changed by the interaction of two waves, and the change in reflectivity is in a large degree insensitive to the input phase difference between the two waves.
Abstract: The reflectivity of a microcavity filled with a quadratic nonlinear material is shown to be actively changed by the interaction of two waves. Within this microcavity, the reflection coefficient of a weak wave at the fundamental frequency is changed from almost 0% to a value in the vicinity of 100% by the simultaneous incidence of an intense wave at the second-harmonic frequency. This change in reflectivity is shown to be in a large degree insensitive to the input phase difference between the two waves.
Abstract: This chapter provides a theoretical background of the optical properties of semiconductor quantum nanostructures and emphasizes on how those properties vary from quantum wells to quantum dots and how they are influenced by the exciton effect. Semiconductor quantum wells in which a thin semiconductor film is sandwiched between different materials via heterojunctions confine electron motion in the two-dimensional thin-film plane. This two-dimensionality gives rise to new optical properties that are not observed in bulk materials: (1) such as optical absorption and gain spectra peculiar to the step like density of states, (2) strong exciton resonance clearly observable even at room temperature, and (3) large optical nonlinearity and an electric field-induced energy shift of the resonance, called the “quantum-confined Stark effect.” Multidimensional quantum-confinement structures, such as quantum wires and quantum dots, are expected to improve quantum-effect optical devices.
Patent•
31 Aug 1999TL;DR: In this article, a three-dimensional waveguiding structure for a microcavity surface-emitting laser is described in which native aluminum oxide layers provide control of intracavity waveguide and the laser optical mode structure of the emitted beam.
Abstract: A three-dimensional waveguiding structure for a microcavity surface-emitting laser is described in which native aluminum oxide layers provide control of intracavity waveguiding and the laser optical mode structure of the emitted beam. Microcavity lasers described herein account for the blueshift of the emission wavelength as the laser lateral dimensions are reduced to or below the emission wavelength.
TL;DR: In this paper, a planar resonant-cavity light-emitting diodes have been optimized to meet optical interconnect requirements to increase the extraction efficiency into a given numerical aperture.
Abstract: Planar resonant-cavity light-emitting diodes have been optimized to meet optical interconnect requirements The microcavity effect is exploited to increase the extraction efficiency into a given numerical aperture and to reduce the crosstalk in parallel optical interconnect applications Devices are fabricated with an overall quantum efficiency of 37% into a polymer optical fiber with a numerical aperture of 05 and a FWHM beam divergence angle of 105/spl deg/ at a drive current of 1 mA
TL;DR: In this article, the authors studied two-photon nonlinear optical effects arising in a microcavity geometry from resonant twophoton absorption or second-harmonic generation.
Abstract: We have studied two-photon nonlinear optical effects arising in a microcavity geometry from resonant two-photon absorption or second-harmonic generation The transmission spectrum of the cavity is shown to depend on light intensity according to a simple two-level picture with an intensity-dependent coupling: at resonance the system exhibits a two-photon Rabi splitting The absorption spectrum of a weak probe beam in a pumped cavity is found to strongly depend on pump intensity and detuning; the resulting effect is a sort of two-photon analogue of the usual optical Stark effect For moderate pump intensities a two-level picture with a pump-dependent coupling can account for the main results, while at higher intensities new unexpected features show up; in particular, we predict the appearance of gain in well-determined spectral regions due to hyper-Raman processes Finally, we have shown how the coupling coefficients appearing in our formalism can be obtained from a detailed knowledge of the material and geometrical properties of a specific system For illustrative purposes, we have estimated the required light intensities using realistic data for a GaAs-based semiconductor microcavity
TL;DR: In this paper, the (2+1)-dimensional problem is reduced to a tractable form, by means of a semianalytical method, by exploiting a previously introduced model valid for both passive and active configurations of a multiple-quantum-well device, when a small modulated optical signal is applied.
Abstract: Cavity solitons were recently predicted in semiconductor microresonators grown with a vertical geometry. By exploiting a previously introduced model valid for both passive and active configurations of a multiple-quantum-well device, we studied the response in the time domain offered by such self-organized structures in the device, when a small modulated optical signal is applied. Using appropriate symmetry considerations, the (2+1)-dimensional problem is reduced to a tractable form, by means of a semianalytical method. We demonstrated that large differential-gain factors, competitive with those of other all-optical and some opto-electronic devices, are attainable, when the output signal is collected at the peak of the cavity soliton. This fact, in connection with the reconfigurability properties already established for cavity soliton arrays, allows to conceive different schemes for optical information handling: feasible arrangements for parallel amplification and for signal commutation are proposed.
TL;DR: In this article, a systematic investigation of the emission properties of semiconductor microcavity light-emitting diodes (MC-LEDs) with different cavity detuning is presented.
Abstract: We report a systematic investigation of the emission properties of semiconductor microcavity light-emitting diodes (MC-LEDs) with different cavity detuning. Evidence that varying the cavity detuning leads to temperature insensitive output characteristics is provided by changes in the temperature dependence of the slope efficiency extracted from the light output versus current characteristics. For resonantly tuned devices the slope efficiency decreases monotonically with increasing temperature. However when the cavity peak is detuned to long wavelength with respect to the room temperature quantum well (QW) emission, temperature insensitive characteristics are achieved. Compared to a noncavity type LED, enhanced efficiency and narrow spectral linewidth have been observed for the MC-LEDs with the highest output efficiency achieved when the QW emission and cavity peak are exact resonant.
TL;DR: In this article, the authors derived the field distribution including third-order nonlinearity in a quantum well microcavity structure, and an expression of intersubband optical absorption was obtained.
Abstract: On the basis of a local-field theory, the field distribution including third-order nonlinearity in a quantum well microcavity structure is derived, and an expression of intersubband optical absorption is thus obtained. It is found that local-field corrections at certain condition can act as a positive feedback so that a bistability can be established. In a quantum well microcavity structure, by changing the length of the cavity, the angle of incidence, the field confinement and the line widths, one can effectively detune the local-field feedback so that the threshold intensity and the `S'-type loop of the optical bistability can be modified.
TL;DR: In this paper, the properties of porous silicon microcavities impregnated with a laser dye are investigated by photoluminescence and reflection measurements, and the spontaneous emission spectrum of the optically excited rhodamine 800 is drastically modified by micro-cavity effects: the peak emission intensity is increased, the linewidth is narrowed.
Abstract: The properties of porous silicon microcavities impregnated with a laser dye are investigated by photoluminescence and reflection measurements. The spontaneous emission spectrum of the optically excited rhodamine 800 is drastically modified by microcavity effects: the peak emission intensity is increased, the linewidth is narrowed. These results demonstrate that using all porous silicon or dye-filled microcavities provides new possibilities to improve the properties of photonic devices.
TL;DR: In this paper, optically pumped resonant cavity emitters and vertical cavity surface-emitting lasers based on epitaxial CdHgTe material are reported. The Fabry-Perot resonator is constituted by two postgrowth dielectric mirrors.
TL;DR: In this paper, a modified spontaneous emission rate in quantum dot microcavity arrays is presented, which is achieved by using apertured micro-cavities with square aperture sizes varied from 5 to 1 μm on a side.
Abstract: Data are presented on modified spontaneous emission rates in quantum dot microcavity arrays. Three-dimensional optical confinement is achieved using apertured microcavities with square aperture sizes varied from 5 to 1 μm on a side. A maximum measured increase in the on-resonance spontaneous emission rate over that off resonance is ∼50%, and we identify this enhancement with apertured modes of the microcavity. Oscillations in the spontaneous emission rate versus wavelength correspond to spectral resonances in the higher order aperture modes.
TL;DR: In this paper, specific forms of the travelling and trapped vector mode functions for a three-dimensional Fabry-Perot cavity are developed from the general results of the preceding paper, with parameters describing the output cavity mirror chosen for a typical high Q cavity case.
Abstract: Specific forms of the travelling and trapped vector mode functions for a three-dimensional Fabry-Perot cavity are developed from the general results of the preceding paper, with parameters describing the output cavity mirror chosen for a typical high Q cavity case. Cavity and external quasi-mode functions associated with the quasi-mode theory of macroscopic canonical quantization are then obtained via an idealized choice of output mirror parameters. The coupling constants describing photon exchange processes between the single cavity quasi-mode associated with each Fabry-Perot resonance and various external quasi-modes are calculated, and their slow dependence on the external quasi-mode frequency shows that the conditions for irreversible Markovian damping of the cavity quasi-mode are satisfied. For radiative atoms placed in the cavity the coupling constants for energy exchange processes with sideways travelling external quasi-modes also vary slowely, so that Markovian spontaneous emission damping occurs for the radiative atoms. However, their coupling with the isolated cavity quasi-modes is associated with reversible photon exchanges as represented via one photon Rabi frequencies. The standard model in cavity quantum electrodynamics, in which the basic processes are described by a cavity damping rate, a radiative atom spontaneous decay rate and an atom-cavity mode coupling constant has now been justified in terms of the quasi-mode theory of macroscopic canonical quantization.
TL;DR: In this paper, the spontaneous emission control for rare earth ions implanted inside planar multidielectric microcavities is investigated experimentally, and the modifications induced by the cavity on the emission spectrum, the radiation pattern and the lifetime are studied.
TL;DR: In this paper, the directional enhancement of photoluminescence for nonresonant excitation from cavity polaritons in the distributed feedback (DFB) waveguide microcavities when a cavity standing...
Abstract: We observed the directional enhancement of photoluminescence (PL) for nonresonant excitation from cavity polaritons in the distributed feedback (DFB) waveguide microcavities when a cavity standing ...