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

11 Oct 1999

Volume 75, Issue 15, pp. 2163-2335

Return to All Sections
back to top
RSS Feeds

A technique for evaluating optical confinement in GaN-based lasing structures

S. Bidnyk, B. D. Little, J. J. Song, and T. J. Schmidt

Appl. Phys. Lett. 75, 2163 (1999); http://dx.doi.org/10.1063/1.124952 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present a technique for evaluating optical confinement in GaN-based lasing structures by studying their spectrally resolved near-field pattern under high optical excitation. Emission spectra were found to be strongly dependent on the position of the collection optics relative to the active region when the sample was excited above the lasing threshold. The spatially resolved spectra contain a modulation signature that can be used to deduce the optical confinement characteristics. We show that the observed index-guided modes result from multiple internal reflections at angles very close to the critical angle for total internal reflection between the semiconductor layers with different refractive indices. This technique was used to evaluate the degree of optical confinement in GaN epilayers and GaN/AlGaN separate confinement heterostructures. The implications of this study on the design of GaN-based laser diodes are discussed. © 1999 American Institute of Physics.
Show PACS
42.60.By Design of specific laser systems
42.55.Px Semiconductor lasers; laser diodes

Double-chirped semiconductor mirror for dispersion compensation in femtosecond lasers

R. Paschotta, G. J. Spühler, D. H. Sutter, N. Matuschek, U. Keller, M. Moser, R. Hövel, V. Scheuer, G. Angelow, and T. Tschudi

Appl. Phys. Lett. 75, 2166 (1999); http://dx.doi.org/10.1063/1.124953 (3 pages) | Cited 7 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A double-chirped mirror structure with broadband negative dispersion was realized with semiconductor technology. The necessary high precision of the fabrication was achieved by using special calibration structures. A single reflection on the obtained low-loss mirror produces sufficient negative dispersion for dispersion compensation in a femtosecond laser cavity. In this way we demonstrate 200 fs pulses from a compact Nd:glass laser without any additional dispersion compensation. © 1999 American Institute of Physics.
Show PACS
42.79.Bh Lenses, prisms and mirrors
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.86.+b Optical workshop techniques
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.55.Rz Doped-insulator lasers and other solid state lasers

Spectral analysis of InGaAs/GaAs quantum-dot lasers

P. M. Smowton, E. J. Johnston, S. V. Dewar, P. J. Hulyer, H. D. Summers, A. Patanè, A. Polimeni, and M. Henini

Appl. Phys. Lett. 75, 2169 (1999); http://dx.doi.org/10.1063/1.124954 (3 pages) | Cited 14 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The cause of the unusual spectral distribution, often observed in InGaAs/GaAs quantum-dot lasers, is investigated by analyzing the spectra from devices fabricated with different substrate thickness (100–400 μm). Using a Fourier transform analysis to determine the optical path length, it is found that the measured modulation period correlates with the device thickness. Such a result provides evidence for spectral modulation mediated by the device structure rather than the quantum-dot material itself and is consistent with the idea that the modulation is due to a mode propagating in the transparent substrate. © 1999 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.Fc Modulation, tuning, and mode locking
02.30.Nw Fourier analysis
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)

Optical investigation of infrared dyes in hybrid thin films

M. Casalboni, F. De Matteis, P. Prosposito, and R. Pizzoferrato

Appl. Phys. Lett. 75, 2172 (1999); http://dx.doi.org/10.1063/1.124955 (3 pages) | Cited 16 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on steady-state absorption and emission measurements for two infrared (IR) dye molecules, IR5 and IR1051, incorporated in hybrid organic/inorganic zirconia-based thin films synthesized with a sol-gel technique. For comparison, measurements in liquid solutions have also been carried out, and an estimation of the relative quantum efficiency in solid glassy material with respect to liquid solution is reported. Absorption and emission spectra are discussed in terms of physical and chemical interactions with the host matrix. The present work provides the evidence of successful doping of solid films with dyes for planar waveguides emitting in the infrared region up to 1.3 μm. © 1999 American Institute of Physics.
Show PACS
78.66.-w Optical properties of specific thin films
42.79.Wc Optical coatings
33.20.Ea Infrared spectra
78.30.-j Infrared and Raman spectra
33.50.-j Fluorescence and phosphorescence; radiationless transitions, quenching (intersystem crossing, internal conversion)
78.55.-m Photoluminescence, properties and materials

Enhanced harmonic generation in aperiodic optical superlattices

Ben-Yuan Gu, Bi-Zhen Dong, Yan Zhang, and Guo-Zhen Yang

Appl. Phys. Lett. 75, 2175 (1999); http://dx.doi.org/10.1063/1.124956 (3 pages) | Cited 31 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We find that harmonic generation can be enhanced with aperiodic optical superlattice (AOS) structures realized by inverting poled ferroelectric domains in sample. The optimal design of the AOS can be achieved with use of the simulated annealing method. The constructed AOSs can implement multiple wavelength second-harmonic generation and the coupled third-harmonic generation with an identical effective nonlinear coefficient. The simulations show that the constructed AOSs can enhance harmonic generation compared with the Fibonacci optical superlattice. The physical origin of this enhancement is ascribed to the constructive interference effect. © 1999 American Institute of Physics.
Show PACS
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.79.Wc Optical coatings
78.66.-w Optical properties of specific thin films
77.80.Dj Domain structure; hysteresis

Stress-dependent growth kinetics of ultraviolet-induced refractive index change and defect centers in highly Ge-doped SiO2 core fibers

Tsung-Ein Tsai, Thierry Taunay, and E. Joseph Friebele

Appl. Phys. Lett. 75, 2178 (1999); http://dx.doi.org/10.1063/1.124957 (3 pages)

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The evolution of the index change of type-IIa gratings observed in 28 mol % Ge–SiO2 core fibers with 1.8 μm core diameter under various strains was measured from the optical spectra, and the induced defects at high and low strains were studied with electron spin resonance. Data will be presented to show that the index modulation (Δnmod) of type-IIa gratings is likely associated with Ge E′ centers. © 1999 American Institute of Physics.
Show PACS
42.81.-i Fiber optics
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
61.72.J- Point defects and defect clusters
76.30.Mi Color centers and other defects
42.79.Dj Gratings
78.20.hb Piezo-optical, elasto-optical, acousto-optical, and photoelastic effects

Dithered-edge sampling of terahertz pulses

Jake Bromage, Ian A. Walmsley, and C. R. Stroud

Appl. Phys. Lett. 75, 2181 (1999); http://dx.doi.org/10.1063/1.125396 (3 pages) | Cited 2 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We introduce a technique for ultrawideband measurement of terahertz pulses called dithered-edge sampling (DES). The technique makes use of a photoconductive receiver, but the detection bandwidth is much wider than that of the receiver alone. The key to increasing the bandwidth is the addition of an ultrafast optically triggered attenuator that chops the terahertz pulse before its detection. The bandwidth is limited only by the duration of the optical pulse used to trigger the attenuator. We use a combination of derivative dither and an integrating receiver to recover the terahertz field directly from the measured signal. When used alone, the slow receiver blurs the measured terahertz pulse width to 1.3 ps. However, the increased time resolution of the DES system (triggered attenuator plus receiver) allows one to measure source-limited terahertz pulse widths (400 fs in this case). © 1999 American Institute of Physics.
Show PACS
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
85.60.Gz Photodetectors (including infrared and CCD detectors)
42.65.Re Ultrafast processes; optical pulse generation and pulse compression

Blue emission from Tm-doped GaN electroluminescent devices

A. J. Steckl, M. Garter, D. S. Lee, J. Heikenfeld, and R. Birkhahn

Appl. Phys. Lett. 75, 2184 (1999); http://dx.doi.org/10.1063/1.124958 (3 pages) | Cited 71 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Blue emission has been obtained at room temperature from Tm-doped GaN electroluminescent devices. The GaN was grown by molecular beam epitaxy on Si(111) substrates using solid sources (for Ga and Tm) and a plasma source for N2. Indium–tin–oxide was deposited on the GaN layer and patterned to provide both the bias (small area) and ground (large area) transparent electrodes. Strong blue light emission under the bias electrode was observable with the naked eye at room temperature. The visible emission spectrum consists of a main contribution in the blue region at 477 nm corresponding to the Tm transition from the 1G4 to the 3H6 ground state. A strong near-infrared peak was also observed at 802 nm. The relative blue emission efficiency was found to increase linearly with bias voltage and current beyond certain turn-on levels. © 1999 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
81.05.Ea III-V semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close