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

21 Jul 2008

Volume 93, Issue 3, Articles (03xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 93, 031101 (2008); http://dx.doi.org/10.1063/1.2959092 (3 pages)

Di Xu, Kevin P. Chen, Kris Ohlinger, and Yuankun Lin
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Holographic fabrication of diamondlike photonic crystal template using two-dimensional diffractive optical elements

Di Xu, Kevin P. Chen, Kris Ohlinger, and Yuankun Lin

Appl. Phys. Lett. 93, 031101 (2008); http://dx.doi.org/10.1063/1.2959092 (3 pages) | Cited 9 times

Online Publication Date: 21 July 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This letter demonstrates holographic fabrication of three-dimensional diamondlike photonic crystal templates in SU8 photoresist using a single diffractive optical element. Five coherent laser beams produced by a two-dimensional phase mask were used to construct face-centered-cubic or tetragonal interference patterns. The superposition of two interference patterns through double exposures yields diamondlike photonic crystal templates in SU8. Photonic bandgap calculation reveals a full bandgap in inverse structures based on the template. The utilization of the two-dimensional phase mask simplifies the fabrication configuration in multiple beam holographic lithography for three-dimensional photonic fabrication.
Show PACS
42.40.Eq Holographic optical elements; holographic gratings
42.86.+b Optical workshop techniques
42.70.Qs Photonic bandgap materials
42.40.Kw Holographic interferometry; other holographic techniques

Estimating threshold reduction for spin-injected semiconductor lasers

I. Vurgaftman, M. Holub, B. T. Jonker, and J. R. Meyer

Appl. Phys. Lett. 93, 031102 (2008); http://dx.doi.org/10.1063/1.2957656 (3 pages) | Cited 5 times

Online Publication Date: 21 July 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The magnitude of threshold reduction in a semiconductor laser with electron spin injection is shown to depend on such intrinsic properties of the active region as the dominant recombination mechanism, the ratio of hole-to-electron densities of states, the active-region doping, and the available material gain as well as cavity properties such as the optical loss. The threshold reduction is expected to be greatest when the laser’s active region is undoped, the recombination is strongly dominated by Auger processes, and the threshold gain is low. It can approach a factor of 3.5 for fully spin-polarized electrons in the active region.
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.)

Simultaneous closure of multiple high voltage parallel spark channels without switch: A parametric study

Pallavi Raote, Gautam Patil, J. Padma Nilaya, and Dhruba J. Biswas

Appl. Phys. Lett. 93, 031103 (2008); http://dx.doi.org/10.1063/1.2960997 (3 pages) | Cited 3 times

Online Publication Date: 21 July 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Results of a detailed parametric study of a self-switched mutually inductively coupled high voltage parallel spark preionizer are presented. The maximal behavior exhibited by the breakdown voltage of the parallel gaps with respect to the number of mutually coupled turns has been explained. It has been found that there exists a threshold rise time of the current pulse beyond which simultaneous closure of the parallel gaps is not possible and that this threshold value is independent of the nature and geometry of the cores used for the mutual coupling. The degree of simultaneity of the closure of the self-switched parallel gaps matched that of the conventional operation of such gaps.
Show PACS
52.80.Mg Arcs; sparks; lightning; atmospheric electricity

Effect of waveguide sidewall roughness on the threshold current density and slope efficiency of quantum cascade lasers

Fatima Toor, Deborah L. Sivco, Hao E. Liu, and Claire F. Gmachl

Appl. Phys. Lett. 93, 031104 (2008); http://dx.doi.org/10.1063/1.2962984 (3 pages) | Cited 6 times

Online Publication Date: 21 July 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on a study to determine the effect of waveguide sidewall roughness on quantum cascade (QC) laser performance using two two-wavelength heterogeneous QC laser structures, one with emission wavelengths of 7.0 μm/11.2 μm, and the other with 8.7 μm/12.0 μm. For the range of roughness standard deviation values from about 0.4 to 1.0 μm, for which all four QC lasers were operating, the threshold current density increases by 12%–15% and the slope efficiency decreases by 30%–70% with stronger performance degradation for the shorter wavelength lasers, which is in agreement with a model based on Rayleigh scattering.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Transient carrier transfer in tunnel injection structures

V. G. Talalaev, J. W. Tomm, N. D. Zakharov, P. Werner, U. Gösele, B. V. Novikov, A. S. Sokolov, Y. B. Samsonenko, V. A. Egorov, and G. E. Cirlin

Appl. Phys. Lett. 93, 031105 (2008); http://dx.doi.org/10.1063/1.2963973 (3 pages) | Cited 10 times

Online Publication Date: 23 July 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
InGaAs tunnel injection nanostructures consisting of a single quantum well as injector and a quantum dot layer as emitter are studied by time-resolved photoluminescence spectroscopy. The quantum dot photoluminescence undergoes substantial changes when proceeding from direct quantum dot excitation to quantum well excitation, which causes an indirect population of the dot ground states. This results in a lowered effective carrier temperature within the dots. Results on the carrier transfer versus barrier thickness are discussed within the Wentzel–Kramers–Brillouin approximation. Deviations for barrier thicknesses <5 nm are assigned to the formation of nanobridges that are actually detected by transmission electron microscopy.
Show PACS
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.63.Hs Quantum wells
73.63.Kv Quantum dots
73.40.Gk Tunneling
78.67.De Quantum wells
78.67.Hc Quantum dots

Real-time optical reflectometry enabled by amplified dispersive Fourier transformation

Keisuke Goda, Daniel R. Solli, and Bahram Jalali

Appl. Phys. Lett. 93, 031106 (2008); http://dx.doi.org/10.1063/1.2963974 (3 pages) | Cited 10 times

Online Publication Date: 23 July 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The axial scan rate of optical frequency-domain reflectometry and optical coherence tomography can be increased to megahertz frequencies by dispersive Fourier transformation. However, the fundamental connection between dispersion and loss creates a trade-off between detection sensitivity and acquisition speed. Here we circumvent this predicament by using distributed Raman postamplification of the reflection from the sample. The Raman amplification enables measurement of weak signals, which are otherwise buried in detector noise. It extends the depth range without sacrificing the acquisition speed. Single-shot imaging with improved sensitivity at an axial scan rate of 36.6 MHz is demonstrated.
Show PACS
07.60.Hv Refractometers and reflectometers
42.30.Kq Fourier optics

The effect of doping the M-barrier in very long-wave type-II InAs/GaSb heterodiodes

Darin Hoffman, Binh-Minh Nguyen, Edward Kwei-wei Huang, Pierre-Yves Delaunay, Manijeh Razeghi, Meimei Z. Tidrow, and Joe Pellegrino

Appl. Phys. Lett. 93, 031107 (2008); http://dx.doi.org/10.1063/1.2963980 (3 pages) | Cited 5 times

Online Publication Date: 23 July 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A variation on the standard homodiode type-II superlattice with an M-barrier between the π-region and the n-region is shown to suppress the dark currents. By determining the optimal doping level of the M-superlattice, dark current densities of 4.95 mA/cm2 and quantum efficiencies in excess of 20% have been demonstrated at the moderate reverse bias of 50 mV; allowing for near background-limted performance with a Johnson-noise detectivity of 3.11×1010 cm math/W at 77 K for 14.58 μm cutoff wavelength for large area diodes without passivation. This is comparable to values for the state-of-the-art HgCdTe photodiodes.
Show PACS
85.60.Dw Photodiodes; phototransistors; photoresistors
85.40.Ry Impurity doping, diffusion and ion implantation technology

Thermally assisted magnetic recording on a bit-patterned medium by using a near-field optical head with a beaked metallic plate

Takuya Matsumoto, Kimio Nakamura, Tetsuya Nishida, Hiroyuki Hieda, Akira Kikitsu, Katsuyuki Naito, and Tetsunori Koda

Appl. Phys. Lett. 93, 031108 (2008); http://dx.doi.org/10.1063/1.2960344 (3 pages) | Cited 7 times

Online Publication Date: 23 July 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A near-field optical head with a beaked metallic plate was used for writing marks on a Co/Pd bit-patterned medium with a diameter of 20–25 nm and a pitch of 30 nm. Magnetic-force-microscope images of the medium show that the magnetizations of single bits were selectively reversed by the head. The light-utilization efficiency (defined as the ratio of the absorbed power in the medium to the incident light power) was estimated from the writing condition used and thermal modeling as about 5%.
Show PACS
75.50.Ss Magnetic recording materials
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects

A high speed, postprocessing free, quantum random number generator

J. F. Dynes, Z. L. Yuan, A. W. Sharpe, and A. J. Shields

Appl. Phys. Lett. 93, 031109 (2008); http://dx.doi.org/10.1063/1.2961000 (3 pages) | Cited 35 times

Online Publication Date: 23 July 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A quantum random number generator (QRNG) based on gated single photon detection of an In–GaAs photodiode at gigahertz frequency is demonstrated. Owing to the extremely long coherence time of each photon, each photons’ wave function extends over many gating cycles of the photodiode. The collapse of the photon wave function on random gating cycles as well as photon random arrival time detection events are used to generate sequences of random bits at a rate of 4.01 Mbit/s. Importantly, the random outputs are intrinsically biasfree and require no postprocessing procedure to pass random number statistical tests, making this QRNG an extremely simple device.
Show PACS
03.67.Lx Quantum computation architectures and implementations
85.60.Gz Photodetectors (including infrared and CCD detectors)
85.60.Dw Photodiodes; phototransistors; photoresistors

Fabry–Pérot microcavities with controllable resonant wavelengths in periodic dielectric waveguides

Yao Zhang, Wanwen Huang, and Baojun Li

Appl. Phys. Lett. 93, 031110 (2008); http://dx.doi.org/10.1063/1.2964188 (3 pages) | Cited 3 times

Online Publication Date: 24 July 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Fabry–Pérot microcavities with controllable resonant wavelengths and constant quality factors are constructed by introducing defects in periodic dielectric waveguides. Two-dimensional finite-difference time-domain method is used to simulate the field distributions in the cavities. The simulated electric field profile fits a cosine-Gaussian curve. The quadratic relation between the resonant wavelength and the defect length is theoretically discussed and numerically proved. Simulations show that the resonant wavelength can be simply controlled by shifting cylinders in the defects, and the value of quality factor keeps a constant of about 103.
Show PACS
42.79.Gn Optical waveguides and couplers

Single-frequency, Yb-free, resonantly cladding-pumped large mode area Er fiber amplifier for power scaling

Mark Dubinskii, Jun Zhang, and Igor Kudryashov

Appl. Phys. Lett. 93, 031111 (2008); http://dx.doi.org/10.1063/1.2964189 (3 pages) | Cited 6 times

Online Publication Date: 25 July 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report results for a single-frequency (SF) resonantly cladding-pumped Yb-free large mode area (LMA) erbium-doped fiber amplifier (EDFA) with nearly 50% slope efficiency based on a commercial 20/125 μm Er-doped double-clad LMA fiber with a core numerical aperture of 0.07. We believe that this is the original demonstration of a SF resonantly cladding-pumped LMA EDFA. We obtained a diffraction-limited SF output of 9.3 W, which is also a record power output obtained for resonantly cladding-pumped LMA EDFA.
Show PACS
42.55.Wd Fiber lasers
42.60.By Design of specific laser systems
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close