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

18 Jan 2010

Volume 96, Issue 3, Articles (03xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 96, 033101 (2010); http://dx.doi.org/10.1063/1.3291849 (3 pages)

Ferruccio Pisanello, Luigi Martiradonna, Godefroy Leménager, Piernicola Spinicelli, Angela Fiore, Liberato Manna, Jean-Pierre Hermier, Roberto Cingolani, Elisabeth Giacobino, Massimo De Vittorio, and Alberto Bramati
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Power scaling of widely-tunable monochromatic terahertz radiation by stacking high-resistivity GaP plates

Yi Jiang, Yujie J. Ding, and Ioulia B. Zotova

Appl. Phys. Lett. 96, 031101 (2010); http://dx.doi.org/10.1063/1.3292585 (3 pages) | Cited 7 times

Online Publication Date: 19 January 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A high-resistivity GaP crystal was used to generate monochromatic THz pulses with peak output powers reaching 722 W at 108.1 μm by mixing two coherent beams at about 1 μm based on phase-matched difference-frequency generation. By stacking two and three GaP plates with their second-order nonlinear coefficients being switched between the adjacent ones, we have increased the peak power at 120.3 μm from 433.4 W to 1.36 and 2.36 kW, respectively. 2.36 kW corresponds to the photon conversion efficiency of 25%, which is two orders of magnitude higher than our previous result. In contrast, if they are stacked for having the same sign of the nonlinear coefficients, the wavelength corresponding to the highest peak power is red-shifted to 204.8 and 303.9 μm, respectively. Such a result indicates that there is an optimal interaction length for each specific output wavelength.
Show PACS
72.20.-i Conductivity phenomena in semiconductors and insulators
78.30.Hv Other nonmetallic inorganics

Polarization-charge tunnel junctions for ultraviolet light-emitters without p-type contact

Martin F. Schubert

Appl. Phys. Lett. 96, 031102 (2010); http://dx.doi.org/10.1063/1.3280866 (3 pages) | Cited 3 times

Online Publication Date: 19 January 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Polarization-charge tunnel junctions for ultraviolet light-emitters (λ<360 nm) are modeled using the k⋅p multiband quantum transmitting boundary method. It is shown that polarization-charge tunnel junctions can carry sufficient current to be viable for ultraviolet emitters. Sources of inefficiency in existing ultraviolet emitters are discussed, including poor hole-injection efficiency and optical absorption in the p-type GaN contact layers. It is demonstrated that polarization-charge tunnel junctions can deliver improvements in both areas, by eliminating the need for p-type contacts, and by enabling the use of a p-side-down structure, which is shown to have favorable characteristics for carrier transport compared to conventional p-side-up structures.
Show PACS
85.60.Jb Light-emitting devices

Electron acceleration in vacuum induced by a tightly focused chirped laser pulse

Jian-Xing Li (栗建兴), Wei-Ping Zang (臧维平), and Jian-Guo Tian (田建国)

Appl. Phys. Lett. 96, 031103 (2010); http://dx.doi.org/10.1063/1.3294634 (3 pages) | Cited 10 times

Online Publication Date: 19 January 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electron acceleration in vacuum induced by a tightly focused chirped laser pulse has been studied. For a fixed laser output power, the tightly focused chirped laser pulse can accelerate electrons to much higher energies. Focusing laser down to the order of wavelength requires inclusion of terms of third order at least in the diffraction angle ε in the description of the associated field. Retained electron energy depends strongly on frequency chirp parameter and initial position of the electron. Besides, retained energy increases with laser intensity, pulse duration, and initial velocity of electron, and varies periodically with laser constant phase.
Show PACS
42.79.-e Optical elements, devices, and systems
42.60.Fc Modulation, tuning, and mode locking
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.25.Fx Diffraction and scattering

Graded photonic crystal terahertz quantum cascade lasers

Y. Chassagneux, R. Colombelli, W. Maineult, S. Barbieri, S. P. Khanna, E. H. Linfield, and A. G. Davies

Appl. Phys. Lett. 96, 031104 (2010); http://dx.doi.org/10.1063/1.3273056 (3 pages) | Cited 14 times

Online Publication Date: 20 January 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The use of integrated photonic structures to tailor the behavior of light is extremely promising for optimizing performance and for introducing advanced functionalities into optoelectronic devices. We demonstrate a powerful method based on photonic-band engineering which allows the optimization of the resonator quality factors of devices operating on band-edge photonic-crystal states. We also show that carefully designed π-shifts in two-dimensional photonic-resonators give enhanced beam properties. The application of these general techniques to terahertz quantum cascade lasers yields improved maximum operating temperatures, and angularly narrow, single-lobed surface emission of ≈ 12°×8°. The devices operate at ≈2.8/2.9 THz, with peak output powers of 5 mW at 78 K.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
85.60.-q Optoelectronic devices

Spectral modulation of ultraviolet femtosecond laser pulse by molecular alignment of CO2, O2, and N2

Yongdong Wang, Xiaomin Dai, Jian Wu, Liang’en Ding, and Heping Zeng

Appl. Phys. Lett. 96, 031105 (2010); http://dx.doi.org/10.1063/1.3292017 (3 pages) | Cited 2 times

Online Publication Date: 20 January 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate efficient third harmonic generation of a near infrared femtosecond pulse through cascaded frequency doubling and sum-frequency generation processes, where the group velocity mismatching between the involved fundamental and generated second harmonic pulses, before they are sent to frequency mixing, are precompensated with a properly inserted nonlinear crystal. The spectrum of the generated third harmonic pulse with energy of 1.1 mJ is further modulated by using impulsive molecular alignments of CO2, O2, and N2, where significantly broadened spectrum in the ultraviolet spectral region is observed due to the additional cross-focusing effect from the parallel aligned molecules and the consequently enhanced self-phase modulation.
Show PACS
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation

Mode locking of ceramic Nd:yttrium aluminum garnet with graphene as a saturable absorber

W. D. Tan, C. Y. Su, R. J. Knize, G. Q. Xie, L. J. Li, and D. Y. Tang

Appl. Phys. Lett. 96, 031106 (2010); http://dx.doi.org/10.1063/1.3292018 (3 pages) | Cited 49 times

Online Publication Date: 20 January 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The mode-locking of a ceramic Nd:yttrium aluminum garnet (YAG) solid-state laser (SSL) with solution processed graphene as saturable absorber (SA) was demonstrated. Transform-limited pulses with duration of 4 ps centered at 1064 nm were generated for a nondispersion compensated Nd:YAG SSL. Z-scan studies revealed that the graphene SA has a saturation intensity of 0.87 M W cm−2 and a normalized modulation depth of 17.4%. Our results illustrate the potential of using graphene as a mode locker for SSLs.
Show PACS
42.60.Fc Modulation, tuning, and mode locking
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.55.Rz Doped-insulator lasers and other solid state lasers
42.60.By Design of specific laser systems

Photonic crystal cavities in silicon dioxide

Yiyang Gong and Jelena Vučković

Appl. Phys. Lett. 96, 031107 (2010); http://dx.doi.org/10.1063/1.3297877 (3 pages) | Cited 15 times

Online Publication Date: 21 January 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
One dimensional nanobeam photonic crystal cavities fabricated in silicon dioxide are considered in both simulation and experiment. Quality factors of over 104 are found via simulation, while quality factors of over 5×103 are found in experiment, for cavities with mode volumes of 2.0(λ/n)3 and in the visible wavelength range 600–716 nm. The dependences of the cavity quality factor and mode volume for different design parameters are also considered.
Show PACS
78.67.Pt Multilayers; superlattices; photonic structures; metamaterials
42.70.Qs Photonic bandgap materials

High extraction efficiency light-emitting diodes based on embedded air-gap photonic-crystals

Elison Matioli, Elizabeth Rangel, Micheal Iza, Blaise Fleury, Nathan Pfaff, James Speck, Evelyn Hu, and Claude Weisbuch

Appl. Phys. Lett. 96, 031108 (2010); http://dx.doi.org/10.1063/1.3293442 (3 pages) | Cited 21 times

Online Publication Date: 22 January 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This letter reports on high extraction efficiency light-emitting diodes (LEDs) based on embedded two-dimensional air-gap photonic crystals (PhCs). High refractive index contrast provided by the air gaps along with high interaction of the embedded PhCs with the guided light resulted in an efficient extraction of all guided modes in the LED, in contrast to the common surface PhC configuration. Embedded PhC LEDs presented an enhanced directional light emission compared to non-PhC LEDs. High extraction efficiency, close to unity, provided by the encapsulated embedded PhC LEDs demonstrates the capability of this approach to achieve high efficiency devices with directional light emission.
Show PACS
85.60.Jb Light-emitting devices

Slow-light-enhanced single quantum dot emission in a unidirectional photonic crystal waveguide

S. J. Dewhurst, D. Granados, D. J. P. Ellis, A. J. Bennett, R. B. Patel, I. Farrer, D. Anderson, G. A. C. Jones, D. A. Ritchie, and A. J. Shields

Appl. Phys. Lett. 96, 031109 (2010); http://dx.doi.org/10.1063/1.3294298 (3 pages) | Cited 10 times

Online Publication Date: 22 January 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the observation of a Purcell enhancement of the in-plane spontaneous emission rates of InAs self-assembled quantum dots coupled to a mode of a unidirectional photonic crystal waveguide fabricated in GaAs(001). Three-dimensional finite-difference time-domain simulations predict the existence of high quality-factor modes due to the slow light resonances of the waveguide. These modes have been observed experimentally with microphotoluminescence and produce enhanced in-plane emission when resonant with a quantum dot.
Show PACS
78.66.Fd III-V semiconductors
78.55.Cr III-V semiconductors
42.79.Gn Optical waveguides and couplers
42.65.Wi Nonlinear waveguides
42.70.Qs Photonic bandgap materials

Density-dependent carrier dynamics in a quantum dots-in-a-well heterostructure

R. P. Prasankumar, W. W. Chow, J. Urayama, R. S. Attaluri, R. V. Shenoi, S. Krishna, and A. J. Taylor

Appl. Phys. Lett. 96, 031110 (2010); http://dx.doi.org/10.1063/1.3294309 (3 pages) | Cited 2 times

Online Publication Date: 22 January 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The incorporation of semiconductor quantum dots into different heterostructures for applications in nanoscale lasing and amplification has been an active area of research in recent years. Here, we use ultrafast differential transmission spectroscopy to temporally and spectrally resolve density-dependent carrier dynamics in a quantum dots-in-a-well (DWELL) heterostructure. We observe excitation-dependent shifts of the quantum dot energy levels at low densities, while at high densities we observe an anomalous induced absorption at the quantum dot excited state that is correlated with quantum well population dynamics. These studies reveal unique Coulomb interaction-induced phenomena with important implications for DWELL-based lasers and amplifiers.
Show PACS
73.63.Kv Quantum dots
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
78.67.Hc Quantum dots
78.55.Cr III-V semiconductors
78.47.J- Ultrafast spectroscopy (<1 psec)

Ring cavity induced threshold reduction in single-mode surface emitting quantum cascade lasers

Elvis Mujagić, Michele Nobile, Hermann Detz, Werner Schrenk, Jianxin Chen, Claire Gmachl, and Gottfried Strasser

Appl. Phys. Lett. 96, 031111 (2010); http://dx.doi.org/10.1063/1.3292021 (3 pages) | Cited 6 times

Online Publication Date: 22 January 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present ring cavity surface emitting (RCSE) quantum cascade lasers operating at temperatures as high as 380 K and above. A reduction in threshold current density and enhanced radiation efficiency are observed as compared to Fabry–Pérot (FP) lasers. In continuous wave, the maximum operation temperature of RCSE lasers is 50 K higher than in FP emitters. The devices exhibit single-mode emission at a wavelength around 8 μm with a side mode suppression ratio of 30 dB at room temperature. A lithographic tuning of the resonance is achieved by a variation in the grating period. The emitters exhibit a low divergent ring-shaped beam pattern with a lobe separation of ∼ 1.5°.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.79.Dj Gratings
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Mode locking of an external-cavity bisection GaInN blue-violet laser diode producing 3 ps duration optical pulses

Kyosuke Saito, Hideki Watanabe, Takao Miyajima, Masao Ikeda, and Hiroyuki Yokoyama

Appl. Phys. Lett. 96, 031112 (2010); http://dx.doi.org/10.1063/1.3292025 (2 pages) | Cited 10 times

Online Publication Date: 22 January 2010

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Passive mode locking of a bisectional GaInN quantum well laser diode was confirmed with external-cavity geometry. Optical pulses of 3 ps duration were produced by controlling the reverse-bias voltage applied to a saturable absorber section. These are the shortest optical pulses ever generated from GaN-based laser diodes.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.Fc Modulation, tuning, and mode locking
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close