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9 Dec 1996

Volume 69, Issue 24, pp. 3623-3756

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Single‐step fabrication of strongly confining quasiphase‐matching waveguides in LiTaO3

Cangsang Zhao and Reinhart Engelmann

Appl. Phys. Lett. 69, 3623 (1996); http://dx.doi.org/10.1063/1.117003 (3 pages)

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Strongly confining waveguides were fabricated in LiTaO3 at high temperature (540–610 °C) by short‐time (≤6 s) rapid thermal annealing. Single‐step photolithography is able to accomplish the simultaneous fabrication of a waveguide and a periodically domain‐inverted structure for second‐order quasiphase‐matching blue‐light generation. A measured normalized conversion efficiency of 7%/W cm2 for a physical length of 0.55 mm in a planar quasiphase‐matching waveguide showed that this single‐step process can lead to high conversion efficiency in channel waveguides. © 1996 American Institute of Physics.
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42.82.Et Waveguides, couplers, and arrays
42.82.Cr Fabrication techniques; lithography, pattern transfer
42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation

The effect of substrate misorientation on the photoluminescence properties of GaN grown on sapphire by metalorganic chemical vapor deposition

P. A. Grudowski, A. L. Holmes, C. J. Eiting, and R. D. Dupuis

Appl. Phys. Lett. 69, 3626 (1996); http://dx.doi.org/10.1063/1.117004 (3 pages) | Cited 22 times

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We report the growth and photoluminescence (300 and 4.2 K) characterization of unintentionally doped GaN on both exact and vicinal (0001) sapphire substrates. The GaN heteroepitaxial layers are grown by metalorganic chemical vapor deposition on sapphire substrates using various growth conditions. The (0001) Al2O3 c‐plane substrates are oriented exactly (0001) or misoriented either 2° towards the a plane (1120), 5° towards the m plane (1010), or 9° toward the m plane. A comparison of the 300 and 4.2 K optical characteristics of the samples grown on the different substrates indicates that a higher photoluminescence intensity is measured for the films on misoriented substrates. © 1996 American Institute of Physics.
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78.55.Cr III-V semiconductors
81.05.Ea III-V semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Photoassisted poling induced second harmonic generation with in‐plane anisotropy in azobenzene containing polymer films

X. L. Jiang, L. Li, J. Kumar, and S. K. Tripathy

Appl. Phys. Lett. 69, 3629 (1996); http://dx.doi.org/10.1063/1.117005 (3 pages) | Cited 12 times

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Photoassisted poling of azobenzene containing polymer films at room temperature using polarized Ar+ laser beam as pump light was studied. Irradiating the films with p‐polarized pump light at an incident angle to the normal during the poling process, second harmonic generation with in‐plane anisotropy could be induced. Second order nonlinear optical coefficient, d33, of the poled sample was measured to be 20 pm/V. The second harmonic generation properties induced by photoassisted poling and thermal assisted poling were compared. © 1996 American Institute of Physics.
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42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.70.Jk Polymers and organics
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials

Terahertz measurements of resonant planar antennas coupled to low‐temperature‐grown GaAs photomixers

K. A. McIntosh, E. R. Brown, K. B. Nichols, O. B. McMahon, W. F. DiNatale, and T. M. Lyszczarz

Appl. Phys. Lett. 69, 3632 (1996); http://dx.doi.org/10.1063/1.117006 (3 pages) | Cited 18 times

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Resonant slot and dipole antennas coupled to low‐temperature‐grown GaAs photomixers have been fabricated and tested at terahertz operating frequencies. Enhanced output power is seen from the resonant structures compared to mixers coupled to broadband self‐complementary spiral antennas. Driving point impedances as high as 300 Ω are attained at the resonant frequencies. These devices will be useful as fixed frequency local oscillators for submillimeter heterodyne receivers. © 1996 American Institute of Physics.
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42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
84.40.-x Radiowave and microwave (including millimeter wave) technology

Tailoring the birefringence in a vertical‐cavity semiconductor laser

A. K. Jansen van Doorn, M. P. van Exter, and J. P. Woerdman

Appl. Phys. Lett. 69, 3635 (1996); http://dx.doi.org/10.1063/1.117007 (3 pages) | Cited 22 times

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We demonstrate a technique to modify the strain in a planar vertical‐cavity semiconductor laser. The technique consists of locally melting a hole in the wafer next to the device by means of a focused laser beam. This allows manipulating both the magnitude and the orientation of the native birefringence in a permanent way. © 1996 American Institute of Physics.
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42.55.Px Semiconductor lasers; laser diodes
78.20.Fm Birefringence

Single‐mode and single‐beam emission from surface emitting laser diodes based on surface‐mode emission

A. Köck, A. Golshani, R. Hainberger, E. Gornik, and L. Korte

Appl. Phys. Lett. 69, 3638 (1996); http://dx.doi.org/10.1063/1.117008 (3 pages) | Cited 4 times

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Single‐mode and single‐beam emission have been achieved from surface emitting laser diodes based on the surface‐mode‐emission technique. By employing an optimized device design and a first‐order grating coupler, the laser diodes show under pulsed operation condition a single‐mode emission with a linewidth of 0.11 nm. A power up to 3.6 mW is emitted into a single, surface‐emitted beam, which has a beam divergence of 0.20°. © 1996 American Institute of Physics.
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42.55.Px Semiconductor lasers; laser diodes
85.60.Jb Light-emitting devices

Photoemission from K–Te photocathodes

D. Bisero, B. M. van Oerle, G. J. Ernst, J. W. J. Verschuur, and W. J. Witteman

Appl. Phys. Lett. 69, 3641 (1996); http://dx.doi.org/10.1063/1.117009 (3 pages) | Cited 3 times

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In this letter the photoemissive properties of K–Te films produced under ultrahigh vacuum conditions are reported. K–Te photocathodes were fabricated by vapor deposition of Te and K onto a Mo substrate into the preparation chamber of the Free Electron Laser of the University of Twente. The highest quantum efficiency obtained at 259 nm was 11.1%, measured just after evaporation; this value decreased in a few minutes to a stable quantum efficiency of 8.3%. The reported results show that K–Te can be considered a promising material for the use as a photocathode in photoinjectors. © 1996 American Institute of Physics.
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79.60.Dp Adsorbed layers and thin films
85.60.Ha Photomultipliers; phototubes and photocathodes
41.60.Cr Free-electron lasers

Potential of confocal microscopes to resolve in the 50–100 nm range

M. Schrader, S. W. Hell, and H. T. M. van der Voort

Appl. Phys. Lett. 69, 3644 (1996); http://dx.doi.org/10.1063/1.117010 (3 pages) | Cited 10 times

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We determine the resolution of high‐performance confocal microscopes by measuring the three‐dimensional point–spread function (3D‐PSF) of an optimized confocal setup. The 3D‐PSF is standardized by recording the scattered light of pointlike objects. For a wavelength of 543 nm and a specified numerical aperture of 1.4 (oil), we find an axial and lateral focal full width at half‐maximum (FWHM) of 460±20 and 145±10 nm, respectively. A high signal‐to‐noise ratio is obtained by using recording times comparable to those of near‐field scanning optical microscopy. We further reduce the effective PSF extent by means of a three‐dimensional deconvolution technique exploiting the information gained from the measurement of the focus. We show that it is possible to obtain an axial and lateral FWHM of the far‐field effective PSF after deconvolution of 80 and 40 nm, respectively. © 1996 American Institute of Physics.
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07.60.Pb Conventional optical microscopes
42.30.Va Image forming and processing

Transient response of wavelength switching in multicavity mode‐locked laser diodes

A. P. Kanjamala and A. F. J. Levi

Appl. Phys. Lett. 69, 3647 (1996); http://dx.doi.org/10.1063/1.117011 (3 pages) | Cited 5 times

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We report the transient response of wavelength switching in multicavity laser diodes. Spatially separated Bragg gratings embedded in a single fiber are used to map optical emission wavelength to photon round‐trip time in an external cavity mode‐locked laser diode. Transient emission wavelength and mode‐locked pulse formation are explored by switching applied radio frequency modulation. Initial conditions are found to dominate transient response. A hot photon cavity has a characteristic rise time corresponding to approximately two photon cavity round trips. A cold photon cavity exhibits significant turn‐on delay and rise time that depends on applied radio frequency signal power and is independent of above threshold steady‐state current bias. © 1996 American Institute of Physics.
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42.55.Px Semiconductor lasers; laser diodes
42.60.Fc Modulation, tuning, and mode locking
85.60.Jb Light-emitting devices

Microfabrication of an electroluminescent polymer light emitting diode pixel array

Salman Noach, Erez Z. Faraggi, Gil Cohen, Yair Avny, Ronny Neumann, Dan Davidov, and Aaron Lewis

Appl. Phys. Lett. 69, 3650 (1996); http://dx.doi.org/10.1063/1.117012 (3 pages) | Cited 35 times

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We describe a method to microfabricate a light emitting diode array with pixels based on conjugated electroluminescent polymers sandwiched between appropriate electrodes. This method, based on direct photoablation with the 193 nm emission of an excimer laser, maintains the properties of these unique polymers. The technique as described here has already achieved an array of 20 μm×20 μm pixels with enhanced electroluminescence (EL) from these pixels and possible spectral tuning of the EL by the application of varying external field. This method can be extended to achieve nanometer dimensionalities using near‐field nanolithography. © 1996 American Institute of Physics.
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85.60.Pg Display systems
78.60.Fi Electroluminescence
78.66.Qn Polymers; organic compounds

Measurement of optical gain at 670 nm in an oxazine‐doped polyimide planar waveguide

Martin N. Weiss, Ramakant Srivastava, Ricardo R. B. Correia, J. F. Martins‐Filho, and Cid B. de Araujo

Appl. Phys. Lett. 69, 3653 (1996); http://dx.doi.org/10.1063/1.117013 (3 pages) | Cited 5 times

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Optical gain measurements have been performed on several of the lower order modes of a multimode polyimide planar waveguide doped with the laser dye cresyl violet 670. A transverse pumping geometry was employed, resulting in larger gain for higher order modes. In a 21‐mm‐long device, an amplification of 14.4 dB was achieved for the sixth order guided mode at a wavelength of 670 nm. The photostability performance of the waveguide is comparable to the results reported for rhodamine‐doped organically modified silica gels. © 1996 American Institute of Physics.
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42.70.Jk Polymers and organics
42.82.Et Waveguides, couplers, and arrays
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Small‐astigmatism, low‐noise, and high‐power self‐sustained pulsation multiple‐quantum‐well laser diodes with a real refractive index guided self‐aligned structure

T. Takayama, O. Imafuji, T. Hashimoto, M. Yuri, A. Yoshikawa, and K. Itoh

Appl. Phys. Lett. 69, 3656 (1996); http://dx.doi.org/10.1063/1.117014 (3 pages) | Cited 1 time

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We demonstrated low‐noise and high‐power GaAlAs laser diodes with small astigmatism. The low‐noise characteristics are realized by self‐sustained pulsation due to the saturable absorption of a single‐quantum‐well located close to the triple‐quantum‐well active layer. The high‐power and small‐astigmatism characteristics are achieved by using a real refractive index guided self‐aligned structure. The lasers showed a relative intensity noise less than −130 dB/Hz under 10% optical feedback in a very wide output‐power range (5–35 mW), a stable fundamental transverse mode up to 150 mW, and astigmatism less than 1 μm. © 1996 American Institute of Physics.
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42.55.Px Semiconductor lasers; laser diodes
78.66.Fd III-V semiconductors
42.60.Rn Relaxation oscillations and long pulse operation

Electric‐field induced cylindrical lens, switching and deflection devices composed of the inverted domains in LiNbO3 crystals

M. Yamada, M. Saitoh, and H. Ooki

Appl. Phys. Lett. 69, 3659 (1996); http://dx.doi.org/10.1063/1.117015 (3 pages) | Cited 44 times

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Three kinds of electro‐optic devices composed of the inverted domains in LiNbO3 substrates were fabricated. The devices are induced and controlled by applying an electric field. The three devices are: (i) a cylindrical lens with an aperture of 340 μm and length of 10 mm, which can tune the focusing length from 20 to 50 mm depending on an electric field ranging from 250 to 150 V/mm, (ii) an optical switching device composed of a periodically inverted domain structure, which can reflect the whole power of an incident light beam by applying an electric field of 700 V/mm, and (iii) a deflection device with a deflection angle of about 5°, depending on an electric field of 750 V/mm. © 1996 American Institute of Physics.
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42.79.Bh Lenses, prisms and mirrors
42.79.Fm Reflectors, beam splitters, and deflectors
42.79.Ta Optical computers, logic elements, interconnects, switches; neural networks
42.82.-m Integrated optics

PtSi–n–Si Schottky‐barrier photodetectors with stable spectral responsivity in the 120–250 nm spectral range

K. Solt, H. Melchior, U. Kroth, P. Kuschnerus, V. Persch, H. Rabus, M. Richter, and G. Ulm

Appl. Phys. Lett. 69, 3662 (1996); http://dx.doi.org/10.1063/1.117016 (3 pages) | Cited 19 times

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Front‐illuminated PtSi–n–Si Schottky barrier photodiodes have been developed for the ultraviolet and vacuum ultraviolet spectral range. Their spectral responsivity was determined in the 120–500 nm spectral range by use of a cryogenic electrical substitution radiometer operated with spectrally dispersed synchrotron radiation. For wavelengths below 250 nm, the spectral responsivity is about 0.03 A/W, comparable to that of GaAsP Schottky photodiodes. Unlike the GaAsP diodes, the new PtSi–n–Si diodes have a spatially uniform response which is virtually stable after prolonged exposure to short wavelength radiation. Even after a radiant exposure of 150 mJ cm−2 at wavelength 120 nm, the relative reduction in spectral responsivity remains below 0.2%. Due to these features, this type of photodiode is a promising candidate for use as secondary detector standard in the ultraviolet and vacuum ultraviolet spectral ranges. © 1996 American Institute of Physics.
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42.88.+h Environmental and radiation effects on optical elements, devices, and systems
85.60.Gz Photodetectors (including infrared and CCD detectors)
29.40.Wk Solid-state detectors
73.30.+y Surface double layers, Schottky barriers, and work functions

Enhancement of beam coupling in the near infrared for tin hypothiodiphosphate

Serguey G. Odoulov, Alexander N. Shumelyuk, George A. Brost, and Kevin M. Magde

Appl. Phys. Lett. 69, 3665 (1996); http://dx.doi.org/10.1063/1.117017 (3 pages) | Cited 9 times

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By using the moving grating technique, without an applied electric field, it is possible to significantly increase the steady‐state two‐beam coupling gain in photorefractive Sn2P2S6. Another technique of gain enhancement consists of cooling of the sample to −30 °C. The measured data confirm the existence of two out‐of‐phase gratings in Sn2P2S6 generated by charge carriers of different sign, with relaxation times of 70 ms and 500 s. © 1996 American Institute of Physics.
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42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials
42.79.Dj Gratings
42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation

Time‐resolved‐spectrum studies of GaN light emitting diodes

F. S. Choa, J. Y. Fan, P.‐L. Liu, J. Sipior, G. Rao, G. M. Carter, and Y. J. Chen

Appl. Phys. Lett. 69, 3668 (1996); http://dx.doi.org/10.1063/1.117183 (3 pages) | Cited 18 times

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Time‐resolved‐emission spectra of InGaN and GaN light emitting diodes with different device structure are studied. Result shows that the UV generation from bulk materials and blue and green emissions from single quantum well devices are band edge recombination. © 1996 American Institute of Physics.
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85.60.Jb Light-emitting devices
78.47.-p Spectroscopy of solid state dynamics

In vivo laser computed tomographic imaging of human fingers by coherent detection imaging method using different wavelengths in near infrared region

B. Devaraj, M. Takeda, M. Kobayashi, M. Usa, K. P. Chan, Y. Watanabe, T. Yuasa, T. Akatsuka, M. Yamada, and H. Inaba

Appl. Phys. Lett. 69, 3671 (1996); http://dx.doi.org/10.1063/1.117184 (3 pages) | Cited 14 times

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We report in vivo laser computed tomographic images of the proximal interphalangeal joint region of a healthy human volunteer’s index finger. The laser computed tomographic (CT) images were obtained with a highly sensitive coherent detection imaging method that is based on the optical heterodyne detection method. These laser CT images are compared at the wavelengths of 715 nm and 1.064 μm and with images obtained by conventional imaging methods such as x‐ray CT and magnetic resonance imaging. Internal structures of the proximal interphalangeal joint region could be clearly identified in the laser CT images. © 1996 American Institute of Physics.
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42.30.Wb Image reconstruction; tomography
42.62.Be Biological and medical applications
87.59.bd Computed radiography

Silicon micromachined ultrasonic immersion transducers

H. T. Soh, I. Ladabaum, A. Atalar, C. F. Quate, and B. T. Khuri‐Yakub

Appl. Phys. Lett. 69, 3674 (1996); http://dx.doi.org/10.1063/1.117185 (3 pages) | Cited 15 times

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Broadband transmission of ultrasound in water using capacitive, micromachined transducers is reported. Transmission experiments using the same pair of devices at 4, 6, and 8 MHz with a signal‐to‐noise ratio greater than 48 dB are presented. Transmission is observed from 1 to 20 MHz. Better receiving electronics are necessary to demonstrate operation beyond this range. Furthermore, the same pair of transducers is operated at resonance to demonstrate ultrasound transmission in air at 6 MHz. The versatile transducers are made using silicon surface micromachining techniques. Computer simulations confirm the experimental results and are used to show that this technology promises to yield immersion transducers that are competitive with piezoelectric devices in terms of performance, enabling systems with 130 dB dynamic range. The advantage of the micromachined transducers is that they can be operated in high‐temperature environments and that arrays can be fabricated at lower cost. © 1996 American Institute of Physics.
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43.38.Gy Semiconductor transducers
43.35.Bf Ultrasonic velocity, dispersion, scattering, diffraction, and attenuation in liquids, liquid crystals, suspensions, and emulsions
07.10.Cm Micromechanical devices and systems

High Q merit factor, low frequency acoustic resonant modes from a Pt{100} single crystal

T. Mitrelias, S. Kelling, M. Gruyters, and D. A. King

Appl. Phys. Lett. 69, 3677 (1996); http://dx.doi.org/10.1063/1.117186 (3 pages) | Cited 2 times

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A spectroscopic technique, acoustic wave resonance spectroscopy (AWRS), has been developed to study the influence of long wavelength acoustic phonon excitations on surface chemical processes. Results are presented which demonstrate the sensitivity of AWRS to the state and composition of a Pt{100} single crystal sample, using an ultrahigh frequency and amplitude resolution acoustic spectrometer, a vector analyzer. A novel part of the ultrahigh vacuum compatible excitation system is a retractable piezo holder allowing the lithium niobate piezo transducer to be moved in situ into the bonding position against the side of the sample. Very sharp acoustic resonant modes with a Q merit factor of 1×104 appear only when the sample is clean. Carbon contamination reduces drastically both the intensity and the density of the peaks. © 1996 American Institute of Physics.
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43.35.Yb Ultrasonic instrumentation and measurement techniques
68.35.Gy Mechanical properties; surface strains
07.64.+z Acoustic instruments and equipment

Line‐focus acoustic microscopy measurements of elastic constants for materials with high acoustic velocities

Ailie Tourlog, Wei Li, and Jan D. Achenbach

Appl. Phys. Lett. 69, 3680 (1996); http://dx.doi.org/10.1063/1.117187 (3 pages) | Cited 3 times

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A method to determine elastic constants of high acoustic velocity materials by line‐focus acoustic microscopy is presented. To determine elastic constants the distances between the specular reflection peak and the first interference maximum and minimum of the V(z) curve measured by line‐focus acoustic microscopy were compared to the corresponding distances obtained from a V(z) measurement model that simulates the experiment. Elastic constants of a single‐crystal diamond sample were determined by this method. © 1996 American Institute of Physics.
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43.35.Cg Ultrasonic velocity, dispersion, scattering, diffraction, and attenuation in solids; elastic constants
43.35.Sx Acoustooptical effects, optoacoustics, acoustical visualization, acoustical microscopy, and acoustical holography
62.20.D- Elasticity
07.64.+z Acoustic instruments and equipment

Measurement of non‐Maxwellian electron energy distributions in an inductively coupled plasma

T. Hori, M. D. Bowden, K. Uchino, and K. Muraoka

Appl. Phys. Lett. 69, 3683 (1996); http://dx.doi.org/10.1063/1.117188 (3 pages) | Cited 17 times

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The electron energy distribution function (EEDF) in an argon planar inductively coupled plasma was measured by the method of laser Thomson scattering. In a low‐pressure discharge, a clear departure from a Maxwellian distribution function was observed; an unambiguous measurement of a non‐Maxwellian distribution in a low‐density glow discharge. The non‐Maxwellian EEDF became Maxwellian in a higher pressure discharge. These observations were attributed to the lack of randomizing collisions in the low‐pressure discharge and the increase in the number of these collisions at higher pressure. © 1996 American Institute of Physics.
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52.80.Hc Glow; corona
52.70.Kz Optical (ultraviolet, visible, infrared) measurements

X‐ray spectroscopic studies of hot, dense iron plasma formed by subpicosecond high intensity KrF laser irradiation

K. Nazir, S. J. Rose, A. Djaoui, G. J. Tallents, M. G. Holden, P. A. Norreys, P. Fews, J. Zhang, and F. Failles

Appl. Phys. Lett. 69, 3686 (1996); http://dx.doi.org/10.1063/1.117189 (3 pages) | Cited 27 times

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The time‐integrated x‐ray emission from a hot, dense iron plasma has been recorded. The iron plasma was created when a target with a 1000‐Å‐thick iron layer buried beneath 1000 Å of plastic was irradiated by a 300 fs pulse of 249 nm laser light at an intensity of approximately 1017 W cm−2. Two models have been used to construct a synthetic x‐ray spectrum. The first employs detailed, spectroscopically accurate atomic data and the second uses a local thermodynamic equilibrium opacity model. The detailed model shows fairly good agreement with experiment whereas the opacity model only shows agreement in the gross features. © 1996 American Institute of Physics.
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52.25.Os Emission, absorption, and scattering of electromagnetic radiation
52.50.Jm Plasma production and heating by laser beams (laser-foil, laser-cluster, etc.)
52.70.La X-ray and γ-ray measurements

Measurement of elastic force on a scanned probe near a solid surface

M. A. Drummond Roby and G. C. Wetsel

Appl. Phys. Lett. 69, 3689 (1996); http://dx.doi.org/10.1063/1.117190 (3 pages) | Cited 7 times

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The physical nature of the forces acting between a laterally vibrating probe in air near a solid surface has been investigated using a calibrated method for the experimental determination of dynamic force. The frequency response of the probe vibrating near its fundamental bending resonance was measured as a function of distance as the probe approached the surface. The experimental results were compared with a continuum‐mechanical model of bending waves in a rod; the nature of the forces was inferred by determining the effect of various boundary conditions on the standing‐wave motion of the probe. The results conclusively show that while in the initial stage of approach the force is dominated by fluid‐dynamic effects, in the final stage of approach an elastic force appears. The appearance of the elastic deformation is characterized by a shift in the resonant frequency of the vibrating probe. © 1996 American Institute of Physics.
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07.79.-v Scanning probe microscopes and components
68.35.Ja Surface and interface dynamics and vibrations
62.20.Qp Friction, tribology, and hardness

Formation of self‐aligned CoSi2 on selective epitaxial growth silicon layer on (001)Si inside 0.1–0.6 μm oxide openings prepared by electron beam lithography

J. Y. Yew, H. C. Tseng, L. J. Chen, K. Nakamura, and C. Y. Chang

Appl. Phys. Lett. 69, 3692 (1996); http://dx.doi.org/10.1063/1.117191 (3 pages) | Cited 7 times

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The self‐aligned formation of CoSi2 was achieved on the selective epitaxial growth (SEG) silicon layer on (001)Si inside 0.1–0.6 μm oxide openings prepared by electron beam lithography. The uniform, high quality SEG Si layer was grown by ultrahigh vacuum chemical vapor deposition at 560 °C with Si2H6. Self‐aligned CoSi2 film without lateral growth of silicide was grown on the SEG Si layer by rapid thermal annealing at 700 °C in N2 ambient. The successful integration of the self‐aligned CoSi2 and SEG of Si processes promises to be a viable process technology for the future deep submicron devices. © 1996 American Institute of Physics.
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85.40.Hp Lithography, masks and pattern transfer
68.55.-a Thin film structure and morphology
85.40.Sz Deposition technology

Interwell carrier transport in InGaAsP multiple quantum well laser structures

K. Fröjdh, S. Marcinkevičius, U. Olin, C. Silfvenius, B. Stålnacke, and G. Landgren

Appl. Phys. Lett. 69, 3695 (1996); http://dx.doi.org/10.1063/1.117192 (3 pages) | Cited 14 times

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We present direct measurements of interwell carrier transport in InGaAsP quantum well (QW) laser structures performed by time‐resolved photoluminescence. Conditions of originally empty and filled wells are explored. In both cases, the time for the hole transport across the structure is found to be of the order of tens of picoseconds. Comparison of experimental results and simulations allowed us to develop an adequate interwell carrier transport model that includes thermionic capture/emission over the QW interfaces and drift/diffusion in the barrier regions. We show that dynamic consideration of carrier densities and band bending for each QW are essential. © 1996 American Institute of Physics.
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73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
78.66.Fd III-V semiconductors
78.47.-p Spectroscopy of solid state dynamics
42.70.Hj Laser materials
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