Superfluorescence of Ion Beam Synthesized Dense-Packed Embedded CdSe Nanoclusters

2004 ◽  
Vol 829 ◽  
Author(s):  
H. Karl ◽  
I. Groβhans ◽  
P. Huber ◽  
B. Stritzker
Keyword(s):  
Thermal Treatment ◽  
Size Distribution ◽  
Laser Power ◽  
Ion Beam ◽  
Excitation Power ◽  
Electronic Energy ◽  
Linear Increase ◽  
Pump Laser ◽  
High Dose ◽  
Electronic Energy Transfer

Dense-packed embedded semiconductor quantum dot (QD) layers with a multimodal size distribution are representing new types of QD solids. Their optical and electronic properties are modified due to dipole-dipole interactions and tunneling effects. In this work sequential high dose ion implantation of Cd and Se and subsequent thermal treatment is used to synthesize QD assemblies with the required structural properties in the surface near region of 500 nm thick thermally grown SiO2 on Silicon. We used cw photoluminescence (PL) to study PL-yield as a function of pump laser power at low temperatures for different various stoichiometries and annealing conditions. In these embedded QD assemblies of mixed size distribution we detected a promising non-linear increase of the PL-intensity with laser excitation power. The exponents evaluated are maximal for implanted Cd:Se-dose ratios between 0.8 and 1.0. The power law dependence of the PL-yield on pump laser power will be discussed in context with electronic energy transfer between dense-packed QD's of different size, implanted dose ratios and postimplantation thermal treatment conditions.

scholarly journals Mev Ion Beam Induced Index of Refraction Changes in Layered GaAs/AlGaAs Waveguides

1995 ◽  
Vol 396 ◽  
Author(s):  
T. Taylor ◽  
D. Ila ◽  
R. L. Zimmerman ◽  
P. R. Ashley ◽  
D. B. Poker
Keyword(s):  
Ion Beam ◽  
Beam Current ◽  
Electronic Energy ◽  
Index Of Refraction ◽  
Propagation Loss ◽  
Carbon Ions ◽  
Practical Applications ◽  
Oxygen Ions ◽  
Electronic Energy Transfer ◽  
Channel Waveguides

AbstractPreviously, we showed that localized optical modifications could be produced without subsequent post thermal annealing in selectively masked planar GaAs/Al 4Ga6As waveguide structures using 10 MeV oxygen ions. In our present investigation, irradiation experiments were performed on masked GaAs/Al 4Ga6As waveguide samples at 298 K using 10 MeV oxygen and 8 MeV carbon ions. The two ion incident energies were chosen to yield the maximum electronic stopping power near the interface septing the top cladding layer and the guiding layer. This localized modification process emphasizes the crucial role that the electronic energy transfer plays on the degree to which the refractive index of the guiding layer is altered. Propagation loss measurements on the fabricated channel waveguides were performed by end fire coupling a laser diode source at a wavelength of 1.3 μm. Observation of the extracted propagation loss values reveal that further optimization of the ion beam pmeters are required before practical applications can be achieved. The relative efficiency of the various ions to induce optically altered regions which serve as lateral confinement barriers of laser light shows that this fabrication process is sensitive to the ion beam current.

scholarly journals Damming an Electronic Energy Reservoir: Ion-regulated Electronic Energy Shuttling in a [2]Rotaxane

2021 ◽  
Author(s):  
Shilin Yu ◽  
Gediminas Jonusauskas ◽  
Jean-Luc Pozzo ◽  
Stephen Goldup ◽  
Vicente Martí Centelles ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Electronic Energy ◽  
Electronic Energy Transfer

We demonstrate the first example of bidirectional reversible electronic energy transfer (REET) between the mechanically bonded components of a rotaxane. Our prototypical system was designed such that photoexcitation of a...

Spectroscopic confirmation of reversible electronic energy transfer in methylglyoxal

1975 ◽  
Vol 63 (1) ◽  
pp. 593-594 ◽  
Author(s):  
R. L. Opila ◽  
R. A. Coveleskie ◽  
James T. Yardley
Keyword(s):  
Energy Transfer ◽  
Electronic Energy ◽  
Electronic Energy Transfer

Vibrational relaxation and electronic energy transfer ofN2aggregates in solid Xe matrices

1985 ◽  
Vol 31 (8) ◽  
pp. 4854-4865 ◽  
Author(s):  
H. Kühle ◽  
J. Bahrdt ◽  
R. Fröhling ◽  
N. Schwentner ◽  
H. Wilcke
Keyword(s):  
Energy Transfer ◽  
Vibrational Relaxation ◽  
Electronic Energy ◽  
Electronic Energy Transfer

Excitation Power Dependence of Photoluminescence in CIB and FIB Implanted Superlattices

1991 ◽  
Vol 240 ◽  
Author(s):  
A. G. Choo ◽  
H. E. Jackson ◽  
P. Chen ◽  
A. J. Steckl ◽  
V. Gupta ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Peak Position ◽  
Excitation Power ◽  
Excitation Intensity ◽  
Power Dependence ◽  
Photoluminescence Spectra ◽  
Multiple Scan ◽  
Donor Acceptor ◽  
Low Temperature Photoluminescence

ABSTRACTLow temperature photoluminescence spectra have been used to characterize conventional ion beam (CIB) and focused ion beam (FIB) implanted superlattices. The excitation dependence of the single scan FIB is found to be significantly different from CIB and multiple scan FIB implantations which are similar. The peak position of the donor-acceptor transition is observed to change to higher energies significantly slower with excitation intensity for the single scan FIB case when compared to the multiple scan FIB and CIB cases. Simple models to describe these effects are briefly discussed.

Carbon Overcoat Loss From the Surface of a Heat Assisted Magnetic Storage Disk due to Laser Irradiation

2013 ◽  
Author(s):  
Paul M. Jones ◽  
Joachim Ahner ◽  
Christopher L. Platt ◽  
Huan Tang ◽  
Julius Hohlfeld
Keyword(s):  
Curie Temperature ◽  
Laser Power ◽  
Single Point ◽  
Magnetic Layer ◽  
Pump Laser ◽  
Probe Laser ◽  
Magnetic Storage ◽  
Carbon Overcoat ◽  
Fept Alloy ◽  
The Media

A pump-probe experimental technique that incorporated a 527nm wavelength pump laser and a 476nm probe laser was applied to a magnetic storage disk having a magnetic layer comprised of a FePt alloy and coated with a hydrogenated carbon overcoat (COC). The pump laser power was systematically increased while sweeping the applied field with an electromagnet to observe the temperature dependent magnetization, which is proportional to the change in the polarization of the reflected beam. In this way the laser power required to heat the media to the Curie temperature (Tc) was determined, with the Curie temperature of the media determined from a separate magnetometry measurement. Such a single point laser power-to-media temperature calibration allowed the determination of the media temperature over a small laser power range near Tc. The carbon over-coated FePt media was then irradiated for varying durations at temperatures pertinent to a Heat Assisted Magnetic Recording (HAMR) device [1]. The COC surface topography and carbon bonding structure within each irradiated zone was probed with AFM and micro-spot Raman. A subtle, systematic temperature and duration dependent change in the COC was observed. With increasing temperature and duration, the Raman D-peak became increasingly pronounced, signaling an increase of the sp2 (disorder) content in the film in the irradiated region. At incrementally higher temperatures, the loss of the carbon overcoat becomes apparent as a shallow depression in the COC film in the irradiated area. A clearer picture of the possible sensitivity and kinetics of the loss of COC on the HAMR media surface was obtained by measuring its loss over a range of irradiation temperatures and durations. The activation energy and COC loss rate were obtained and a possible mechanism for COC failure-loss was discussed within the bounds of the operating HAMR device [2].

Electronic energy transfer in beam pumped gas mixtures

1974 ◽  
Vol 10 (9) ◽  
pp. 752-752
Author(s):  
R. Hill ◽  
D. Eckstrom ◽  
R. Gutcheck ◽  
D. Huestis ◽  
D. Lorents ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Gas Mixtures ◽  
Electronic Energy ◽  
Electronic Energy Transfer
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