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

24 May 1999

Volume 74, Issue 21, pp. 3081-3230

Return to All Sections
back to top
RSS Feeds

Collisional broadening and shift of spectral lines in quantum dot lasers

A. V. Uskov, K. Nishi, and R. Lang

Appl. Phys. Lett. 74, 3081 (1999); http://dx.doi.org/10.1063/1.124068 (3 pages) | Cited 30 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We estimate homogeneous broadening and shift of optical transition lines in self-assembled quantum dots (SAQD) caused by elastic Coulomb collisions of carriers in wetting layer with carriers in the SAQD. In particular, we demonstrate that the dephasing time for lasing transitions can be ∼0.1–1 ps at carrier densities in wetting layer ∼ 1015 m−2. © 1999 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
78.66.-w Optical properties of specific thin films
73.61.-r Electrical properties of specific thin films

Improved operational stability of polyfluorene-based organic light-emitting diodes with plasma-treated indium–tin–oxide anodes

J. S. Kim, R. H. Friend, and F. Cacialli

Appl. Phys. Lett. 74, 3084 (1999); http://dx.doi.org/10.1063/1.124069 (3 pages) | Cited 95 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the influence of various surface treatments of indium–tin–oxide (ITO) anodes on the operational stability of high-efficiency (up to 8.2 lm/W) green-emitting polymer light-emitting diodes (PLEDs), employing a doped poly(3,4-ethylene dioxythiophene), hole transport layer, a polyfluorene based emissive layer, and Ca–Al cathodes. The anodes were modified by physical (oxygen-plasma), chemical (aquaregia), and combined treatments. Oxygen plasma improves the stability under constant current with respect to all other anodes, with half-brightness (100 cd/m2) lifetimes two to five times longer than for untreated samples, and 1000 times longer than for aquaregia samples. We derive two major indications for optimization of PLEDs. First, thermal management of the diode is of the uppermost importance and there is significant scope for improvement. Second, the ITO anode and in general the electrical properties of the hole-injecting contact are crucial to device operation, even in the presence of a hole transport layer. © 1999 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
42.70.Jk Polymers and organics
81.65.Cf Surface cleaning, etching, patterning
52.77.Bn Etching and cleaning
52.77.Dq Plasma-based ion implantation and deposition

Polarization independent phase demodulation using photorefractive two-wave mixing

Philippe Delaye, Alain Blouin, Denis Drolet, Jean-Pierre Monchalin, Louis-Anne de Montmorillon, and Gérald Roosen

Appl. Phys. Lett. 74, 3087 (1999); http://dx.doi.org/10.1063/1.124070 (3 pages) | Cited 6 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We describe both theoretically and experimentally a polarization independent interferometric adaptive photodetector based on photorefractive two-wave mixing. The configuration is based on the simultaneous recording of two independent gratings in a single photorefractive crystal. Applied to the detection of ultrasonic signals, this interferometric photodetector operates with depolarized beams issued from multimode fibers and gives a detection limit close to the ultimate. © 1999 American Institute of Physics.
Show PACS
42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation
42.40.Kw Holographic interferometry; other holographic techniques
43.35.Yb Ultrasonic instrumentation and measurement techniques
42.81.Gs Birefringence, polarization
85.60.Gz Photodetectors (including infrared and CCD detectors)
43.60.Qv Signal processing instrumentation, integrated systems, smart transducers, devices and architectures, displays and interfaces for acoustic systems

Temperature-insensitive operation of real index guided 1.06 μm InGaAs/GaAsP strain-compensated single-quantum-well laser diodes

Hideki Asano, Mitsugu Wada, Toshiaki Fukunaga, and Toshiro Hayakawa

Appl. Phys. Lett. 74, 3090 (1999); http://dx.doi.org/10.1063/1.124071 (3 pages) | Cited 10 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Temperature-insensitive characteristics have been demonstrated in single mode 1.06 μm InGaAs single-quantum-well laser diodes grown by metalorganic vapor phase epitaxy. The large band-gap AlGaInP current blocking layer is employed in the buried-ridge laser structure. Tensile-strained GaAsP barrier layers were used for strain compensation and electron barriers for reducing electron overflow from a quantum well. As a result, almost totally temperature-insensitive light output-current characteristics have been realized. The uncoated device shows the highest record characteristics temperature of 437 K for the threshold current in the range of 20–50 °C. In addition, the slope efficiency does not change over 20–80 °C. © 1999 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)

Small-signal gain and iodine dissociation in a supersonic chemical oxygen–iodine laser with transonic injection of iodine

D. Furman, E. Bruins, B. D. Barmashenko, and S. Rosenwaks

Appl. Phys. Lett. 74, 3093 (1999); http://dx.doi.org/10.1063/1.124072 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Measurements of the gain and temperature in the resonator of a supersonic chemical oxygen–iodine laser (COIL) with transonic injection of I2, using diode laser-based diagnostics, are reported. For conditions corresponding to the maximum chemical efficiency of this type of COIL (11.7 mmole/s of chlorine, no primary buffer gas, and 1.36 mmole/s of the secondary N2), the gain is a nonmonotonous function of the iodine flow rate. Maximum gain of 0.34%/cm is achieved for an iodine flow rate of 0.27 mmole/s. An analytical method is developed which enables the use of these dependencies for calculation of the iodine dissociation fraction F and the number N of O2(1Δ) molecules lost in the region of iodine dissociation per I2 molecule. It is found that F is a nonmonotonous function of the iodine flow rate, its maximum value being small (0.55). © 1999 American Institute of Physics.
Show PACS
42.55.Ks Chemical lasers
78.60.Ps Chemiluminescence
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
82.30.Lp Decomposition reactions (pyrolysis, dissociation, and fragmentation)

Reflection from dual-domains in a holographically-formed polymer-dispersed liquid crystal material

Chris C. Bowley, Gregory P. Crawford, and Haiji Yuan

Appl. Phys. Lett. 74, 3096 (1999); http://dx.doi.org/10.1063/1.124073 (3 pages) | Cited 8 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A holographically-formed polymer-dispersed liquid crystal is reported with two distinctive reflective states brought about by a single laser exposure of a liquid crystal-rich emulsion. The two reflective states are the result of two structurally different domains that are formed during the holographic cure. A simple phenomenological model is presented that describes the dual-domain effect. © 1999 American Institute of Physics.
Show PACS
81.05.Qk Reinforced polymers and polymer-based composites
61.30.-v Liquid crystals
81.40.Tv Optical and dielectric properties related to treatment conditions
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
42.70.Df Liquid crystals
42.40.My Applications
82.70.Kj Emulsions and suspensions

A simple method for optically enhancing the small electro-optical effects of fast switching electroclinic liquid crystals

H. Xu, A. B. Davey, T. D. Wilkinson, and W. A. Crossland

Appl. Phys. Lett. 74, 3099 (1999); http://dx.doi.org/10.1063/1.124074 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report a method for optically enhancing the small electro-optic effect of fast switching liquid crystals in order to allow the liquid-crystal electro-optical devices to operate at very high speed. In comparison with the method using grating-excited guided modes, this method makes device fabrication and operation much easier as the cell structure is similar to a conventional cell but with a metallic mirror coated on the bottom glass substrate. Using this method, a contrast ratio of >5 has been obtained for optical switches with an electro-optical response time of 700 ns and a field of 12 V/μm. © 1999 American Institute of Physics.
Show PACS
42.79.Kr Display devices, liquid-crystal devices
42.79.Ta Optical computers, logic elements, interconnects, switches; neural networks
78.20.Jq Electro-optical effects
42.82.Ds Interconnects, including holographic interconnects
85.60.-q Optoelectronic devices
61.30.Gd Orientational order of liquid crystals; electric and magnetic field effects on order

Design considerations and analytical approximations for high continuous-wave power, broad-waveguide diode lasers

D. Botez

Appl. Phys. Lett. 74, 3102 (1999); http://dx.doi.org/10.1063/1.124075 (3 pages) | Cited 39 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Accurate analytical approximations are derived for the equivalent transverse spot size, d/Γ (<5% error), and the transverse beamwidth θ1/2 (<2% error), of broad-waveguide-type diode lasers, over a wide range in waveguide width: from the first-order-mode cutoff to the third-order-mode cutoff. The analytical formulas are found to be in good agreement with experimental values. For low-series-resistance and thermal-resistance devices, it is found that the junction-temperature rise ΔTj in continuous wave (CW) operation is a strong function of both the characteristic temperature T1 for the external differential quantum efficiency ηD as well as of the heatsink thermal resistance. If the device has relatively temperature-insensitive ηD (i.e., T1≳1000 K) the maximum CW power as well as the power density at catastrophic optical mirror damage, mathCOMD, are limited, for a given active-region material, only by the heatsink heat-removal ability. For large d/Γ, 0.97 μm emitting, 100 μm stripe InGaAs/InGaAs(P)/GaAs devices with T1 = 1800 K, record-high CW and quasi-CW (100 μs wide pulses) output powers are obtained. The ratio of quasi-CW to CW mathCOMD values is only 1.3, in contrast to devices of poor carrier confinement and subsequent low-T1 values (∼140 K), for which the ratio is 1.9, and whose maximum CW powers are ∼40% less than those obtainable from high-T1 devices. © 1999 American Institute of Physics.
Show PACS
42.60.By Design of specific laser systems
42.55.Px Semiconductor lasers; laser diodes
42.60.Pk Continuous operation
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Piezoelectric and electro-optic coefficients of the molecular nonlinear optical crystal 2-furyl methacrylic anhydride

P. Kerkoc, S. Maruo, S. Horinouchi, and K. Sasaki

Appl. Phys. Lett. 74, 3105 (1999); http://dx.doi.org/10.1063/1.124076 (2 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Large crystals of 2-furyl methacrylic anhydride were successfully grown, making it possible to measure accurately their piezoelectric and electro-optic coefficients. Low modulation frequency electro-optic coefficients at a wavelength of 632.8 nm are: r33 = 7.1±0.4 pm/V and r13 = 4.5±0.2 pm/V, whereas the inverse piezoelectric coefficients are: d33 = 8.2±0.4 pm/V and d13 = 2.2±0.1 pm/V. © 1999 American Institute of Physics.
Show PACS
42.70.Jk Polymers and organics
77.65.Bn Piezoelectric and electrostrictive constants
77.84.Jd Polymers; organic compounds
78.20.Jq Electro-optical effects
42.70.Mp Nonlinear optical crystals

Depth-resolved imaging of nematic liquid crystals by third-harmonic microscopy

D. Yelin, Y. Silberberg, Y. Barad, and J. S. Patel

Appl. Phys. Lett. 74, 3107 (1999); http://dx.doi.org/10.1063/1.124077 (3 pages) | Cited 10 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Third-harmonic microscopy is shown to be a powerful tool for the study of liquid crystal structures. The third-harmonic probe enables the investigation of molecular order well inside a liquid crystal cell. The observation of phase transition in various nematic liquid crystal samples is presented as a demonstration for the power of this technique. For example, nematic and isotropic regions are shown to coexist across the depth of the cell. Thermal fluctuations are observed in the nematic regions close to the isotropic–nematic transition temperature. © 1999 American Institute of Physics.
Show PACS
42.70.Df Liquid crystals
61.30.Eb Experimental determinations of smectic, nematic, cholesteric, and other structures
64.70.M- Transitions in liquid crystals
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
07.60.Pb Conventional optical microscopes

In-plane alignment of noncentrosymmetric molecules by oblique-incidence molecular beam deposition

Bert Müller, Chengzhi Cai, Armin Kündig, Ye Tao, Martin Bösch, Matthias Jäger, Christian Bosshard, and Peter Günter

Appl. Phys. Lett. 74, 3110 (1999); http://dx.doi.org/10.1063/1.124078 (3 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The preferential orientation of noncentrosymmetric, organic molecules with intermolecular bonding is realized by means of oblique-incidence molecular beam deposition. The in-plane anisotropy in the optical properties of the thin films is shown by transmission spectra of ultraviolet light. Second-harmonic generation measurements demonstrate the preferential orientation of the molecules aligned in-plane. In addition, the dependence of the second-harmonic light intensity on the film thickness reveals the dominance of bulk effects with respect to surface contributions. Therefore, this molecular alignment technique is a promising method to produce stable thin films for applications in linear and nonlinear optics. © 1999 American Institute of Physics.
Show PACS
42.70.Jk Polymers and organics
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials
78.66.Qn Polymers; organic compounds
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
81.05.Lg Polymers and plastics; rubber; synthetic and natural fibers; organometallic and organic materials
68.55.-a Thin film structure and morphology
78.20.Ek Optical activity
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
78.40.Me Organic compounds and polymers

Infrared and self-frequency doubled laser action in Yb3+-doped LiNbO3:MgO

E. Montoya, J. Capmany, L. E. Bausá, T. Kellner, A. Diening, and G. Huber

Appl. Phys. Lett. 74, 3113 (1999); http://dx.doi.org/10.1063/1.124079 (3 pages) | Cited 43 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Stable continuous-wave laser action in the near-infrared and in the green spectral region has been obtained in a self-frequency doubling solid-state laser, the Yb3+:MgO:LiNbO3 nonlinear crystal. By pumping with a Ti:sapphire laser and using a nearly concentric cavity, laser action at 1.06 μm was achieved with an absorbed power threshold of 101 mW and efficiency around 47%. As much as 60 mW of self-frequency-doubled radiation at 530 nm was also obtained with absorbed pump powers of 800 mW in critical cavity alignment. Efficient laser action was also obtained in the near-infrared region under pumping with diode laser. © 1999 American Institute of Physics.
Show PACS
42.55.Rz Doped-insulator lasers and other solid state lasers
42.70.Hj Laser materials
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.60.By Design of specific laser systems
42.70.Mp Nonlinear optical crystals

Degenerate four-wave mixing in (Pb, La) (Zr, Ti)O3 polycrystalline film fabricated by metalorganic chemical-liquid deposition

G. H. Jin, B. Nemet, Y. L. Lu, C. Hsu, M. Cronin-Golomb, F. L. Wang, H. Jiang, and J. Zhao

Appl. Phys. Lett. 74, 3116 (1999); http://dx.doi.org/10.1063/1.124080 (3 pages) | Cited 12 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have demonstrated a large photorefractive effect in thin-film polycrystalline (Pb, La) (Zr, Ti)O3 (8.5/65/35) fabricated by metalorganic chemical-liquid deposition. With an applied external electric field, this film exhibited a high photorefractive diffraction efficiency measured by degenerate four-wave mixing. Poling phenomena and depolarization processes in the film were also investigated. © 1999 American Institute of Physics.
Show PACS
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials
42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
78.66.Nk Insulators
42.70.Gi Light-sensitive materials
78.20.Jq Electro-optical effects
77.22.Ej Polarization and depolarization
42.40.Eq Holographic optical elements; holographic gratings
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close