scholarly journals Exciton dynamics as a function of excitation intensity and double-pulse excitation in cyanine molecule thin films: Toward low-power optical switches

2019 ◽  
Vol 126 (3) ◽  
pp. 033103
Author(s):  
Osamu Kojima ◽  
Junpei Nagauchi ◽  
Takashi Kita
Keyword(s):  
Thin Films ◽  
Low Power ◽  
Optical Switches ◽  
Excitation Intensity ◽  
Double Pulse ◽  
Pulse Excitation ◽  
Exciton Dynamics

Fabrication and Microstructural Change of PMN-PT Thin Films on Si Substrates by PLD with Mask and Double-Pulse Lazer Excitation

2007 ◽  
Vol 350 ◽  
pp. 111-114 ◽  
Author(s):  
Shogo Hayashi ◽  
Naoki Wakiya ◽  
Takanori Kiguchi ◽  
M. Tanaka ◽  
Kazuo Shinozaki
Keyword(s):  
Thin Films ◽  
Laser Irradiation ◽  
Excimer Laser ◽  
Nd:Yag Laser ◽  
Double Pulse ◽  
Pulse Excitation ◽  
High Deposition Rate ◽  
Si Substrates ◽  
Excimer Laser Irradiation ◽  
Krf Excimer Laser

Epitaxial Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) thin films were fabricated on (La,Sr)CoO3/CeO2/ YSZ coated Si substrates by double-pulse excitation PLD with and without a mask. For double-pulse excitation PLD without a mask in conditions of Nd:YAG laser irradiation before defocused KrF-excimer-laser irradiation, the surface roughness of PMN-PT thin films was rather less than that of the films fabricated using Nd:YAG single laser PLD. Thin films with smoother surfaces were deposited at the high deposition rate of 5.6 nm·min-1 using the mask and the double-pulse excitation PLD method in conditions of irradiation of Nd:YAG laser after KrF excimer laser at 0.5 =s delays.

Fabrication of HfO2 Thin Film on Si Substrate by Double-Pulse Excitation PLD

2007 ◽  
Vol 350 ◽  
pp. 129-132
Author(s):  
Tomohiro Tabara ◽  
Naoki Wakiya ◽  
Takanori Kiguchi ◽  
M. Tanaka ◽  
Kazuo Shinozaki
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Surface Morphology ◽  
Pulsed Laser ◽  
Double Pulse ◽  
Laser Deposition ◽  
Pulse Excitation ◽  
Si Substrate ◽  
Nd:Yag Lasers ◽  
Electrical Insulation Properties

Thin films of HfO2 were fabricated on a p-Si(001) substrate using double pulse excitation (DPE) pulsed laser deposition (PLD) with KrF excimer and Nd:YAG lasers, and using conventional Nd:YAG laser PLD under two typical oxygen pressures (7.3 × 10-2 and 7.3 × 10-1 Pa). At 400°C or higher temperatures, the films are crystalline; at less than 400°C, they are amorphous. At higher oxygen pressures, DPE-PLD was effective against droplets. Then the surface morphology and electrical insulation properties of thin films were improved. At lower pressure, DPE-PLD was ineffective.

A New Deep Acceptor in Epitaxial Cubic SiC

1989 ◽  
Vol 162 ◽  
Author(s):  
J. A. Freitas ◽  
S. G. Bishop
Keyword(s):  
Thin Films ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Excitation Intensity ◽  
Acceptor Pair ◽  
Deep Acceptor ◽  
Intensity Dependence ◽  
Pl Spectra ◽  
Donor Acceptor ◽  
Donor Acceptor Pair

ABSTRACTThe temperature and excitation intensity dependence of photoluminescence (PL) spectra have been studied in thin films of SiC grown by chemical vapor deposition on Si (100) substrates. The low power PL spectra from all samples exhibited a donor-acceptor pair PL band which involves a previously undetected deep acceptor whose binding energy is approximately 470 meV. This deep acceptor is found in every sample studied independent of growth reactor, suggesting the possibility that this background acceptor is at least partially responsible for the high compensation observed in Hall effect studies of undoped films of cubic SiC.

Influence of nanostructure size on the luminescence behavior of silicon nanoparticle thin films

1997 ◽  
Vol 12 (12) ◽  
pp. 3386-3392 ◽  
Author(s):  
A. A. Seraphin ◽  
E. Werwa ◽  
K. D. Kolenbrander
Keyword(s):  
Thin Films ◽  
Quantum Confinement ◽  
Room Temperature ◽  
Silicon Nanoparticles ◽  
Excitation Intensity ◽  
Luminescence Properties ◽  
Photoluminescence Intensity ◽  
High Excitation ◽  
Silicon Thin Films ◽  
Processing Techniques

We demonstrate the effect of particle size and quantum confinement on the luminescence properties of nanoscale silicon thin films. Thin films of agglomerated silicon nanoparticles are synthesized using pulsed laser ablation supersonic expansion. Following deposition, standard semiconductor processing techniques are employed to reduce the nanoparticle size. Films are oxidized both in air and chemically to reduce the silicon core dimensions, resulting in a shift of the luminescence emission peak to shorter wavelengths. Removal of the oxide using hydrofluoric acid (HF) results in further blueshifting of the luminescence, as does subsequent reoxidation in air and using nitric acid. The luminescence properties of samples are also studied as a function of excitation intensity. For room temperature excitation with a pulsed 355 nm source, a saturation of the photoluminescence intensity at high excitation intensity is observed, along with a blueshift of the peak PL wavelength. This behavior is found to persist at reduced temperature. A saturation of PL intensity, but no blueshift, is observed for high excitation intensity using a cw 488 nm source at room temperature. At reduced temperatures, no saturation of emission intensity occurs for high intensity 488 nm cw excitation. Both the irreversible shifting of the peak PL wavelength with size reducing treatments and the PL behavior at high excitation intensities indicate that quantum confinement determines the luminescence wavelength.

scholarly journals Controllable Polarization of Lasing Emission From a Polymer Microfiber Laser

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Van Duong Ta ◽  
Rui Chen ◽  
Handong Sun
Keyword(s):  
Optical Sensors ◽  
Transverse Magnetic ◽  
Optical Switches ◽  
Pulse Excitation ◽  
Whispering Gallery ◽  
Low Threshold ◽  
Output Laser ◽  
On Chip ◽  
Doped Polymer ◽  
Lasing Modes

AbstractMicrolasers with controllable polarization of output emission are vital for on-chip optical communications, optical sensors and optical switches. In this work, we report a high quality (Q) factor, low-threshold polymer microfiber laser and the possibility of achieving laser emission with a desired polarization. The microfiber is fabricated by direct drawing from a dye-doped polymer solution and it can generate whispering gallery mode (WGM) lasing under optical pulse excitation. When the microfiber is pumped from the side with pumping direction perpendicular to the microfiber’s axis, the polarization direction of the output laser is found to be the same as that of the pump laser. Lasing emission with either transverse electric (TE) or transverse magnetic (TM) modes can be obtained and these two polarization states can be switched over by tuning the pumping laser. Furthermore, emission with both TE and TM modes can also be observed by changing the orientation of the microfiber relatively to pumping direction. Our finding provides an effective approach for achieving microlasers that have high Q lasing modes with anticipated polarization.

Micro-hole drilling in thin films with cw low power lasers

2011 ◽  
Vol 1 (4) ◽  
pp. 598 ◽  
Author(s):  
J.C. Ramirez-San-Juan ◽  
J.P. Padilla-Martinez ◽  
P. Zaca-Moran ◽  
R. Ramos-Garcia
Keyword(s):  
Thin Films ◽  
Low Power ◽  
Hole Drilling ◽  
Micro Hole
Sign in / Sign up

Export Citation Format

Share Document