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

12 Oct 1998

Volume 73, Issue 15, pp. 2069-2222

Return to All Sections
back to top
RSS Feeds

A laser pumped ultranarrow bandwidth optical filter

Zhilin Hu and Xizhi Zeng

Appl. Phys. Lett. 73, 2069 (1998); http://dx.doi.org/10.1063/1.122380 (3 pages)

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An atomic optical filter with ultranarrow bandwidth has been developed. This filter has two operating channels generated from two hyperfine energy levels in the Cs ground state with a 9.2 GHz frequency separation. By employing a cw Ti:sapphire laser to alternatively pump the polarized Cs atoms to a selected hyperfine energy level, each of the two channels can be, respectively, used as emitting and receiving terminals. Compared to a normal Faraday anomalous dispersion optical filter, there is an increase in transmittance and a decrease in total equivalent bandwidth in this filter. © 1998 American Institute of Physics.
Show PACS
42.79.Ci Filters, zone plates, and polarizers
42.79.Sz Optical communication systems, multiplexers, and demultiplexers
32.80.Xx Level crossing and optical pumping

1.1 W continuous-wave, narrow spectral width (<1 Å) emission from broad-stripe, distributed-feedback diode lasers (λ = 0.893 μm)

T. Earles, L. J. Mawst, and D. Botez

Appl. Phys. Lett. 73, 2072 (1998); http://dx.doi.org/10.1063/1.122381 (3 pages) | Cited 14 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
By etching a distributed-feedback grating directly into the Al-free optical confinement region of a 100 μm stripe InGaAs/InGaP/GaAs diode laser, 1.1 W cw front-facet output power has been obtained at 0.893 μm with a spectral full width at half maximum of 0.9 Å. These devices have 1 mm long cavities and shallow gratings with a coupling coefficient, κ ∼ 7 cm−1. The combination of long device length and low grating coupling results in both efficient operation as well as a longitudinally uniform field profile. As a result, all excited lateral modes oscillate at the same longitudinal cavity resonance to high power levels. Using shallow gratings etched in an InGaP upper confinement layer permits the growth of a high-quality cladding layer over the grating surface yielding excellent device performance. Facet-coated (5%/95%) devices demonstrate external differential quantum efficiencies of 51% and peak wallplug efficiencies of 32% at 1.1 W cw output power. © 1998 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
42.82.Bq Design and performance testing of integrated-optical systems
42.79.Dj Gratings

Electron–plasmon relaxation in quantum wells with inverted subband occupation

Mikhail V. Kisin, Michael A. Stroscio, Gregory Belenky, and Serge Luryi

Appl. Phys. Lett. 73, 2075 (1998); http://dx.doi.org/10.1063/1.122382 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have considered the electron-plasmon interaction and intersubband resonance screening in a quantum well with inverted subband occupation. We show that in such a system the intersubband plasmon emission leads to an efficient deexcitation of the nonequilibrium initial state and raises the occupation of states at the lower-subband bottom. Downshift and resonance narrowing of the intersubband optical emission spectra are obtained and shown to be influenced by the process of intersubband plasmon excitation. © 1998 American Institute of Physics.
Show PACS
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)

An approach for recording and readout beyond the diffraction limit with an Sb thin film

J. Tominaga, T. Nakano, and N. Atoda

Appl. Phys. Lett. 73, 2078 (1998); http://dx.doi.org/10.1063/1.122383 (3 pages) | Cited 141 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A technique for recording and retrieving small marks beyond the optical diffraction limit was proposed. The basic experiment with this technique was also carried out at a constant linear velocity of 2.0 m/s, rotating a disk with a multi-layered structure of Sb and GeSbTe, which were separated by a thin film of SiN. By use of the optically nonlinear property of the Sb thin film, carrier to noise ratio of more than 10 dB was obtained from recorded marks of 90 nm, using an optical system with the laser wavelength of 686 nm and a numerical aperture of 0.6. © 1998 American Institute of Physics.
Show PACS
42.79.Vb Optical storage systems, optical disks
42.79.Wc Optical coatings
42.25.Fx Diffraction and scattering
42.65.-k Nonlinear optics
42.60.Mi Dynamical laser instabilities; noisy laser behavior
42.55.Px Semiconductor lasers; laser diodes

Photochemical color switching behavior of induced cholesteric liquid crystals for polarizer free liquid crystalline devices

Seiji Kurihara, Tomoko Kanda, Takashi Nagase, and Takamasa Nonaka

Appl. Phys. Lett. 73, 2081 (1998); http://dx.doi.org/10.1063/1.122384 (3 pages) | Cited 18 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Photoresponsive cholesteric (Ch) liquid crystals (LCs) showing reflection of visible light were prepared by the addition of chiral molecules and azobenzene molecules in a host nematic LC. The Ch–isotropic phase transition temperature and wavelength of reflected light were controlled by varying the enantiomer excess. Switching between reflection and transparent states was achieved by ultraviolet irradiation. In addition, the switching time was also explored by means of time-resolved measurements. © 1998 American Institute of Physics.
Show PACS
61.30.Eb Experimental determinations of smectic, nematic, cholesteric, and other structures
64.70.M- Transitions in liquid crystals
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
78.20.-e Optical properties of bulk materials and thin films
82.50.-m Photochemistry

Large frequency range of negligible transmission in one-dimensional photonic quantum well structures

Jian Zi, Jun Wan, and Chun Zhang

Appl. Phys. Lett. 73, 2084 (1998); http://dx.doi.org/10.1063/1.122385 (3 pages) | Cited 74 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We show that it is possible to enlarge the range of low transmission in one-dimensional photonic crystals by using photonic quantum well structures. If a defect is introduced in the photonic quantum well structures, defect modes with a very high quality factor may appear. The transmission of the defect mode is due to the coupling between the eigenmodes of the defect and those at the band edges of the constituent photonic crystals. © 1998 American Institute of Physics.
Show PACS
42.70.Qs Photonic bandgap materials

Theoretical performance of wurtzite and zincblende InGaN/GaN quantum well lasers

R. J. Radtke, U. Waghmare, H. Ehrenreich, and C. H. Grein

Appl. Phys. Lett. 73, 2087 (1998); http://dx.doi.org/10.1063/1.122386 (3 pages) | Cited 5 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The theoretical gain, radiative and Auger recombination rates, and threshold current densities of ideal wurtzite (WZ) and zincblende (ZB) 20 Å In0.2Ga0.8N/70 Å GaN multiple quantum well laser diodes are compared. We obtain upper bounds on device performance, which are based on reliable calculations for both band structure and recombination dependent features and show (1) that the performance of present devices having the ZB and WZ structures are within 20% of each other in InGaN/GaN, and (2) that present performance of the best currently available devices is only a factor of 3–4 below the theoretical limit. Radiative recombination is far more important than Auger processes. The calculations are performed using a superlattice K⋅p formalism and density functional theory within the local-density approximation. The latter yields bulk zone-center energies, wave functions, and directly calculated momentum matrix elements. © 1998 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
78.66.Fd III-V semiconductors

Increasing throughput of a near-field optical fiber probe over 1000 times by the use of a triple-tapered structure

T. Yatsui, M. Kourogi, and M. Ohtsu

Appl. Phys. Lett. 73, 2090 (1998); http://dx.doi.org/10.1063/1.122387 (3 pages) | Cited 54 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We fabricated a new probe with extremely high throughput introducing a triple-tapered structure to reduce the loss in a tapered core, to focus the light, and to excite effectively the HE11 mode. A focused ion beam and selective chemical etching were used for fabrication. Over a 1000-fold increase in the throughput of the triple-tapered probe with the aperture diameter D<100 nm was realized in comparison with the conventional single-tapered probe. Furthermore, due to the third taper with a small cone angle, the localized optical near field on the triple-tapered apertured probe with D = 60 nm has been confirmed. © 1998 American Institute of Physics.
Show PACS
07.79.Fc Near-field scanning optical microscopes
42.81.Wg Other fiber-optical devices

Photothermal displacement measurement of transient melting and surface deformation during pulsed laser heating

Shaochen Chen, Costas P. Grigoropoulos, Hee K. Park, Pieter Kerstens, and Andrew C. Tam

Appl. Phys. Lett. 73, 2093 (1998); http://dx.doi.org/10.1063/1.122388 (3 pages) | Cited 7 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A photothermal displacement method has been developed to probe the pulsed laser-induced transient melting and surface deformation of Ni–P hard disk substrates. A probing He–Ne laser beam is aligned collinearly with the near-infrared nanosecond pulsed heating beam. The He–Ne beam spot is scanned on the microfeatures formed on the sample surface by the pulsed laser heating. The deflection signals show the variation of the feature shape resulting from different pulse energies of the heating laser beam. The transient deflection signal also reveals that the time scale of the surface motion is in the range of several hundred nanoseconds. © 1998 American Institute of Physics.
Show PACS
79.20.Ds Laser-beam impact phenomena
78.20.N- Thermo-optic effects
78.20.nb Photothermal effects
68.35.Rh Phase transitions and critical phenomena
64.70.D- Solid-liquid transitions
65.90.+i Other topics in thermal properties of condensed matter (restricted to new topics in section 65)

Adjustable x-ray phase plate and phase modulator

Igor Polikarpov

Appl. Phys. Lett. 73, 2096 (1998); http://dx.doi.org/10.1063/1.122389 (2 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Diffractive birefringence of a crystal in the x-ray region is shown to be adjustable by high-frequency ultrasonic waves (USWs). An increase in diffractive birefringence can be used for fine tuned transformation of linearly polarized synchrotron radiation into circular polarized x rays by a quarter-wave plate. For a stationary USW, x-ray polarization changes with the ultrasound frequency, providing the design parameters for an x-ray phase modulator. © 1998 American Institute of Physics.
Show PACS
07.85.-m X- and γ-ray instruments
78.20.Fm Birefringence
41.50.+h X-ray beams and x-ray optics
42.79.Hp Optical processors, correlators, and modulators

Self-starting passively mode-locked tunable Cr4+: yttrium–aluminum–garnet laser with a single prism for dispersion compensation

Yongmao Chang, Roman Maciejko, Richard Leonelli, and Anthony Spring Thorpe

Appl. Phys. Lett. 73, 2098 (1998); http://dx.doi.org/10.1063/1.122390 (3 pages) | Cited 2 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A self-starting passive mode-locked Cr4+:yttrium–aluminum–garnet laser that uses a saturable Bragg reflector with a single prism for dispersion compensation instead of the standard prism pair is demonstrated. We observed over 230 mW average output power with a pulse width of 400 fs at center wavelengths shorter than 1.5 μm. The tuning range for cw laser operation extends from 1345 to 1557 nm. The mode-locked pulses are self-starting and tunable from 1420 to 1510 nm by means of lossless prism tuning without aperture. © 1998 American Institute of Physics.
Show PACS
42.60.Fc Modulation, tuning, and mode locking
42.55.Rz Doped-insulator lasers and other solid state lasers
42.60.By Design of specific laser systems
42.70.Hj Laser materials
42.79.Bh Lenses, prisms and mirrors
42.65.Re Ultrafast processes; optical pulse generation and pulse compression

High performance interminiband quantum cascade lasers with graded superlattices

Alessandro Tredicucci, Federico Capasso, Claire Gmachl, Deborah L. Sivco, Albert L. Hutchinson, and Alfred Y. Cho

Appl. Phys. Lett. 73, 2101 (1998); http://dx.doi.org/10.1063/1.122391 (3 pages) | Cited 67 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A new class of quantum cascade lasers is presented. They are based on interminiband transitions in chirped superlattices (SL), where the applied electric field is compensated by the quasielectric field resulting from a gradually varying SL period length and average composition. In this way “flat” minibands can be obtained without the need for dopants. At room temperature record high peak (0.5 W) and average (14 mW) powers are obtained for a laser of 7.6 μm wavelength, with the lowest threshold current densities (5 kA/cm2) reported so far for quantum cascade lasers. The maximum temperature for continuous wave operation is an unprecedented 160 K. © 1998 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
78.66.Fd III-V semiconductors

ZnSe-based blue-green lasers with a short-period superlattice waveguide

S. Ivanov, A. Toropov, S. Sorokin, T. Shubina, A. Lebedev, P. Kop’ev, Zh. Alferov, H.-J. Lugauer, G. Reuscher, M. Keim, F. Fischer, A. Waag, and G. Landwehr

Appl. Phys. Lett. 73, 2104 (1998); http://dx.doi.org/10.1063/1.122392 (3 pages) | Cited 14 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the successful application of alternatively strained short-period superlattices for the waveguide region of optically pumped and injection room-temperature ZnSe-based lasers operating within the 470–523 nm spectral range. The design of optically pumped ZnMgSSe/ZnSSe/ZnCdSe lasers provides extremely low threshold power densities due to the enhanced electronic and optical confinement. Room-temperature BeMgZnSe/ZnCdSe injection lasers with threshold current density of about 750 A/cm2 and characteristic temperature as high as 366 K are demonstrated. The peculiarities of carrier transport across the short-period superlattices are explained by a thermally activated mechanism. © 1998 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes

Frequency dependence of radar cross section for arbitrarily shaped scatterers

Hongwei Liu, Yahia M. M. Antar, Zhendong Shi, and Zhengde Wu

Appl. Phys. Lett. 73, 2107 (1998); http://dx.doi.org/10.1063/1.122393 (3 pages)

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This letter introduces a method to perform frequency dependence of radar cross section for either simple or complex scatters in terms of model measurement. To do so, the expressions of physical scale factor based on the electromagnetic similarity are suggested by means of dimensional analysis, geometric and physical optics approximation. Using the results of model measurement within a small range of frequency, the frequency dependence of an arbitrarily shaped scatterer can be obtained. For the purpose of verification and comparison, some measurements of simple and complex shapes have been carried out. The calculated results agree well with the experimental data on the prototype itself. © 1998 American Institute of Physics.
Show PACS
41.20.Jb Electromagnetic wave propagation; radiowave propagation
84.40.Xb Telemetry: remote control, remote sensing; radar
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close