APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

14 Sep 1998

Volume 73, Issue 11, pp. 1457-1597

Return to All Sections
back to top
RSS Feeds

Trap states of tris-8-(hydroxyquinoline) aluminum and naphthyl-substituted benzidine derivative using thermally stimulated luminescence

E. W. Forsythe, D. C. Morton, C. W. Tang, and Yongli Gao

Appl. Phys. Lett. 73, 1457 (1998); http://dx.doi.org/10.1063/1.122173 (3 pages) | Cited 49 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The bulk trap state properties of a naphthyl-substituted benzidine derivative (NPB) and tris-8-(hydroxyquinoline) aluminum (Alq3) have been measured using thermally stimulated luminescence (TSL). The TSL spectra for both organic materials show significant trap distributions over the temperature range from 8 to 300 K. Using a general order TSL expression, the four peaks in NPB were modeled with trap states centered from 0.20 to 0.05 eV. Alq3 has three TSL peaks over the temperature range, with the peak at 156 K modeled as a distribution of trap states from 0.25 to 0.13 eV. For both materials, the trapping mechanism involves a combination of first and second order emission. NPB and Alq3 have trap states sufficiently deep to influence the carrier transport and recombination process in bilayer organic based light emitting. © 1998 American Institute of Physics.
Show PACS
78.60.Kn Thermoluminescence
71.55.Ht Other nonmetals
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping

Light emission from individual self-assembled InAs/GaAs quantum dots excited by tunneling current injection

K. Yamanaka, K. Suzuki, S. Ishida, and Y. Arakawa

Appl. Phys. Lett. 73, 1460 (1998); http://dx.doi.org/10.1063/1.122174 (3 pages) | Cited 17 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report emission from individual quantum dots excited by tunneling current injection using a scanning tunneling microscope (STM). By scanning the STM tip above the self-assembled InAs quantum dots, a spatially resolved scanning tunneling luminescence (STL) image was measured, which contained a fluorescent circular region with a diameter of 50 nm originating from a single InAs quantum dot. It was found that the spatial resolution of the STL system was about 40 nm, which is mainly due to lateral diffusion of holes injected into a GaAs capping layer grown at low temperature (480 °C). We also obtained STL spectra with a sharp single luminescent peak from a single InAs quantum dot. © 1998 American Institute of Physics.
Show PACS
78.66.Fd III-V semiconductors
78.55.Cr III-V semiconductors
68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
68.37.Ps Atomic force microscopy (AFM)
68.37.Rt Magnetic force microscopy (MFM)
68.37.Uv Near-field scanning microscopy and spectroscopy
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)

Kr excimers produced by soft x rays emitted from a laser-produced plasma

Shoichi Kubodera, Masaki Ikeda, Junji Kawanaka, and Wataru Sasaki

Appl. Phys. Lett. 73, 1463 (1998); http://dx.doi.org/10.1063/1.122175 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have demonstrated an excitation method to produce Kr2∗ by using soft x rays emitted from a laser-produced plasma. We have found that Kr2+ ions were directly produced by photoionization of Kr atoms by soft x rays. The behavior of Kr2∗ emission was similar to that of Kr2+, indicating fast relaxation processes to produce Kr2∗ from Kr2+ during the plasma producing laser pulse. Numerical results based on a photoionization model of Kr reproduced the experimental results, which verified the production of Kr2∗ initiated by the photoionization of Kr. © 1998 American Institute of Physics.
Show PACS
33.80.Eh Autoionization, photoionization, and photodetachment
33.80.Rv Multiphoton ionization and excitation to highly excited states (e.g., Rydberg states)

Photorefractive correlation filtering of time-varying laser speckles for vibration monitoring

Alexei A. Kamshilin, Erik Raita, Kimmo Paivasaari, Timo Jaaskelainen, and Yuri N. Kulchin

Appl. Phys. Lett. 73, 1466 (1998); http://dx.doi.org/10.1063/1.122216 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We proposed and experimentally studied a technique of vibration object monitoring. The technique is based on self-diffraction of the speckle pattern on the adaptive correlation filter recorded in photorefractive Bi12TiO20 crystal. This filter is recorded owing to the light-induced scattering known as fanning effect. The proposed technique is as sensitive as interferometric systems and it is very simple for implementation: neither reference nor readout beam is needed for operation. It is shown that the system has a linear response on the lateral displacement of the object surface and its dynamic range can be easily varied depending on experimental conditions. © 1998 American Institute of Physics.
Show PACS
42.30.Ms Speckle and moiré patterns
42.40.Kw Holographic interferometry; other holographic techniques
42.79.Ci Filters, zone plates, and polarizers
42.62.Eh Metrological applications; optical frequency synthesizers for precision spectroscopy
07.60.Ly Interferometers
42.40.Ht Hologram recording and readout methods
42.40.Eq Holographic optical elements; holographic gratings
06.30.Bp Spatial dimensions (e.g., position, lengths, volume, angles, and displacements)

Enhanced sensitivity near-field scanning optical microscopy at high spatial resolution

H. F. Hamann, A. Gallagher, and D. J. Nesbitt

Appl. Phys. Lett. 73, 1469 (1998); http://dx.doi.org/10.1063/1.122176 (3 pages) | Cited 50 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An apertureless near-field optical-imaging method is presented that achieves high spatial resolution as well as a ∼ 4000-fold increase in detection sensitivity, by exploiting the highly localized enhanced near-field interactions between the sample (e.g., Au nanospheres) and a sharp atomic force microscope tip under evanescent laser field illumination. This represents a general method for optical imaging at ⩽ 2 nm spatial resolution, and is applicable to both resonant (i.e., scattering) as well as nonresonant (i.e., fluorescence, Raman, etc.) spectroscopic methods. © 1998 American Institute of Physics.
Show PACS
07.79.Fc Near-field scanning optical microscopes

The infrared optical functions of AlxGa1−xN determined by reflectance spectroscopy

G. Yu, H. Ishikawa, M. Umeno, T. Egawa, J. Watanabe, T. Soga, and T. Jimbo

Appl. Phys. Lett. 73, 1472 (1998); http://dx.doi.org/10.1063/1.122177 (3 pages) | Cited 30 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Infrared reflectivity measurements have been carried out on samples with structures of GaN/sapphire and AlxGa1−xN/GaN/sapphire as well as sapphire substrates. Analyses of the reflectance data of sapphire using the Kramers–Kronig technique and fitting of the reflectance spectra of GaN and AlxGa1−xN samples using analytical expressions have been made. The high-frequency dielectric constant ϵ∞ and the transverse phonon frequency ωTO, are found to vary from 5.15 to 4.2 and from 559.7 to 586.4 cm−1, respectively, when the composition x is varied from 0 to 0.35 at room temperature. The E2 mode, which arises from the disordered state of the alloys, has been observed in the reflectivity spectrum of AlxGa1−xN, and the intensity of the peak is enhanced by increasing the Al content. © 1998 American Institute of Physics.
Show PACS
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
78.20.-e Optical properties of bulk materials and thin films
78.30.Fs III-V and II-VI semiconductors

Tunnel-junction-connected distributed-feedback vertical-cavity surface-emitting laser

A. N. Korshak, Z. S. Gribnikov, and V. V. Mitin

Appl. Phys. Lett. 73, 1475 (1998); http://dx.doi.org/10.1063/1.122217 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An injection distributed-feedback vertical-cavity surface-emitting laser (VCSEL) with tunnel junctions served as quasi-Ohmic intercontacts (tunnel-junction-connected distributed-feedback VCSEL) is proposed. A periodic structure of vertically stacked double-heterostructure laser diodes connected by low-resistance tunnel junctions forms a vertical distributed-feedback (DFB) laser medium. To minimize the threshold, the DFB structure is placed in a Fabry–Perot cavity designed to match gain layers with the maximums of the optical mode, and the tunnel junctions—with its minimums. The passive regions with tunnel junctions provide effective vertical injection into each active region of this multiple-active-region laser. This DFB VCSEL is expected to have an improved performance, specifically, reduced threshold current and heightened output power. © 1998 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Enhancement of the third-order nonlinear optical response of quantum wells in a semiconductor microcavity

Hajime Ishihara and Kikuo Cho

Appl. Phys. Lett. 73, 1478 (1998); http://dx.doi.org/10.1063/1.122178 (3 pages) | Cited 5 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We discuss the enhancement effect of the third-order nonlinear response of excitons coupled with cavity modes, on the basis of a self-consistent calculation of response field and induced polarization. It is shown that a single framework is enough to describe the spectral features of nonlinear spectra in both strong and weak coupling regimes, where the splitting of coupled modes (cavity polaritons) in linear response is larger and smaller, respectively, than the widths. In the latter regime, the nonlinear signal is strongest at the bare excitonic resonance, and its enhancement due to the cavity effect is remarkable. In the former regime, on the other hand, the nonlinear signal appears at the energy positions of the coupled modes, whose spectral shape represents the reduction of normal-mode splitting due to the nonlinear effect. © 1998 American Institute of Physics.
Show PACS
78.66.-w Optical properties of specific thin films
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
73.20.At Surface states, band structure, electron density of states
71.35.Cc Intrinsic properties of excitons; optical absorption spectra
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems

Decay of ultraviolet-induced optical absorption in Ge-doped SiO2 glass

Motoshi Ohama, Takumi Fujiwara, and Akira J. Ikushima

Appl. Phys. Lett. 73, 1481 (1998); http://dx.doi.org/10.1063/1.122179 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report quantitative measurements on the decay of optical absorption at various elevated temperatures in ultraviolet (UV)-irradiated SiO2 glasses doped with Ge. From the Arrhenius plots of decay time constants, the activation energy of the Ge E′ center in the UV-irradiated glasses has been determined to be 2.4±0.3 eV, while the reported activation energy of Ge E′ decay in UV-poled glasses is 0.4±0.1 eV. The present experimental results strongly suggest that the decay process of the Ge E′ center induced in UV-irradiated glasses is quite different from that in UV-poled glasses. © 1998 American Institute of Physics.  
Show PACS
78.40.Ha Other nonmetallic inorganics
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
61.82.Ms Insulators

Optical implementation of the wavelet transform by using a bacteriorhodopsin film as an optically addressed spatial light modulator

Joby Joseph, F. J. Aranda, D. V. G. L. N. Rao, B. S. DeCristofano, B. R. Kimball, and M. Nakashima

Appl. Phys. Lett. 73, 1484 (1998); http://dx.doi.org/10.1063/1.122180 (3 pages) | Cited 5 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An optical system utilizing the photoinduced dichroism in a bacteriorhodopsin film has been demonstrated for the optical implementation of wavelet transforms. The dichroism, induced by the image of a wavelet filter on a bacteriorhodopsin film leads to polarization rotation of the Fourier components of an image. The polarization-rotated Fourier components of an input scene are analyzed with a polarizer to give the wavelet transform components. The dichroism is induced with beams whose profiles are determined by wavelet filters in order to perform the optical wavelet transform. © 1998 American Institute of Physics.
Show PACS
42.79.Hp Optical processors, correlators, and modulators
78.20.Fm Birefringence
42.79.Ci Filters, zone plates, and polarizers
42.30.Kq Fourier optics
87.15.M- Spectra of biomolecules
78.66.Qn Polymers; organic compounds

Multicolored light emitters on silicon substrates

Supratik Guha and Nestor A. Bojarczuk

Appl. Phys. Lett. 73, 1487 (1998); http://dx.doi.org/10.1063/1.122181 (3 pages) | Cited 42 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate the operation of multicolored light emitting diodes (LEDs) on a silicon wafer using ultraviolet/violet GaN LEDs grown by molecular beam epitaxy on Si(111) in conjunction with organic dye based color converters. These organic converters, applied on top of the nitride diodes, absorb the nitride LED electroluminescence at ∼360 nm, and fluoresce in the green (∼530 nm), and orange (∼600 nm). In this fashion, multicolored light emitters may be made to operate side by side and monolithically on the same Si wafer in an approach that may be attractive for miniature GaN based full color displays. © 1998 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
42.79.Nv Optical frequency converters
42.79.Kr Display devices, liquid-crystal devices
85.60.Pg Display systems

High-speed photorefractive polymer composites

D. Wright, M. A. Díaz-García, J. D. Casperson, M. DeClue, W. E. Moerner, and R. J. Twieg

Appl. Phys. Lett. 73, 1490 (1998); http://dx.doi.org/10.1063/1.122182 (3 pages) | Cited 94 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Two photorefractive polymer composites are presented that exhibit the fastest response times reported to date by an order of magnitude (τg ≈ 5 ms at 1 W/cm2), while maintaining large gain coefficients (Γ ≈ 230 and 130 cm−1). These materials show promise for video-rate optical processing applications. The factors limiting the photorefractive speed in these materials are investigated. © 1998 American Institute of Physics.
Show PACS
42.70.Jk Polymers and organics
78.20.-e Optical properties of bulk materials and thin films
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
78.47.-p Spectroscopy of solid state dynamics

Edge emission observed in heavily boron-doped diamond films epitaxially grown on platinum

Yoshihiro Yokota, Takeshi Tachibana, Koichi Miyata, Koji Kobashi, Akimitsu Hatta, Toshimichi Ito, Akio Hiraki, and Yoshihiro Shintani

Appl. Phys. Lett. 73, 1493 (1998); http://dx.doi.org/10.1063/1.122183 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Cathodoluminescence (CL) spectra of diamond films epitaxially grown on single crystal platinum (111) have been investigated at room temperature and 89 K. It was found that the CL spectra of the heavily boron-doped (>3×1020 cm−3) diamond films of more than 16 μm thickness consist only of a near-edge emission at 248±1 nm (5.00±0.02 eV), while any mid-gap emissions are absent. That result suggests that few defects are in the films. It was also found that the temperature dependence of the 248 nm band is very unique, since its intensity increases as temperature increases. The mechanism of the 248 nm band seems to involve quasi-direct transition. © 1998 American Institute of Physics.
Show PACS
78.60.Hk Cathodoluminescence, ionoluminescence
78.66.Db Elemental semiconductors and insulators
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.15.Kk Vapor phase epitaxy; growth from vapor phase
81.05.ub Fullerenes and related materials
81.05.Cy Elemental semiconductors

High-temperature optically pumped lasing in ZnMgSSe/ZnSe heterostructures grown by metalorganic vapor phase epitaxy

A. L. Gurskii, I. P. Marko, E. V. Lutsenko, G. P. Yablonskii, H. Kalisch, H. Hamadeh, and M. Heuken

Appl. Phys. Lett. 73, 1496 (1998); http://dx.doi.org/10.1063/1.122184 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Lasing and optical properties of ZnMgSSe/ZnSe-, ZnMgSSe/ZnSSe/ZnSe-, and ZnMgSSe/ZnMgSSe/ZnSe-based single- and multiple-quantum-well heterostructures grown by metalorganic vapor phase epitaxy were studied, and the characteristics were found to depend on the excitation intensity Iexc, temperature, and well width. Laser action under transverse optical pumping was achieved only for well widths Lz ≥ 4 nm and optical confinement factors Γ>0.04. In separate confinement heterostructures, lasing with the lowest threshold (Ithr = 10–30 kW/cm2 at T = 78 K) was achieved and device characteristics were studied up to T = 577 K. © 1998 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes

Theory of a self-assembled quantum-dot semiconductor laser with Auger carrier capture: Quantum efficiency and nonlinear gain

A. V. Uskov, Y. Boucher, J. Le Bihan, and J. McInerney

Appl. Phys. Lett. 73, 1499 (1998); http://dx.doi.org/10.1063/1.122185 (3 pages) | Cited 22 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We analyze a self-assembled quantum-dot laser where lasing levels are pumped purely through Auger carrier capture. Analysis shows that Auger carrier capture and Auger transport of carriers between quantum dots can provide effective laser pumping and fast modulation at least up to 10 GHz. Auger carrier transport decreases spectral hole burning, which together with dot-barrier hole burning can damp relaxation oscillations. © 1998 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.50.Hz Strong-field excitation of optical transitions in quantum systems; multiphoton processes; dynamic Stark shift
42.50.Md Optical transient phenomena: quantum beats, photon echo, free-induction decay, dephasings and revivals, optical nutation, and self-induced transparency
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
42.55.Ah General laser theory
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close