Search results for "Excimer laser"
showing 10 items of 31 documents
Luminescence of α-quartz crystal and silica glass under excitation of excimer lasers ArF (193 nm), KrF (248 nm)
2017
This work is supported by Latvian National Program “IMIS2”. We are indebted to I.I. Cheremisin for crystal samples.
Luminescence of natural α-quartz crystal with aluminum, alkali and noble ions impurities
2019
This work was supported by the Latvian Science Council Grant No lzp-2018/1–0289 .
Luminescence of localized states in oxidized and fluorinated silica glass
2019
This work was supported by the Latvian Science Council Grant No lzp-2018/1-0289.
Absorption and luminescence in amorphous SixGe1-xO2 films fabricated by SPCVD
2012
Abstract Optical absorption and photoluminescence of Ge-doped silica films fabricated by the surface-plasma chemical vapor deposition (SPCVD) are studied in the 2–8 eV spectral band. The deposited on silica substrate films of about 10 μm in thickness are composed as x·GeO2-(1-x)·SiO2 with x ranging from 0.02 to 1. It is found that all as‐deposited films do not luminesce under the excitation by a KrF (5 eV) excimer laser, thus indicating lack of oxygen deficient centers (ODCs) in them. After subsequent fusion of silicon containing (x
Luminescence of phosphorus doped silica glass
2017
This work is supported by Material Science program IMIS2 of Latvia.
Study of silica-based intrinsically emitting nanoparticles produced by an excimer laser
2019
International audience; We report an experimental study demonstrating the feasibility to produce both pure and Ge-doped silica nanoparticles (size ranging from tens up to hundreds of nanometers) using nanosecond pulsed KrF laser ablation of bulk glass. In particular, pure silica nanoparticles were produced using a laser pulse energy of 400 mJ on pure silica, whereas Ge-doped nanoparticles were obtained using 33 and 165 mJ per pulse on germanosilicate glass. The difference in the required energy is attributed to the Ge doping, which modifies the optical properties of the silica by facilitating energy absorption processes such as multiphoton absorption or by introducing absorbing point defect…
First observation of a resonance ionization signal on242mAm fission isomers
1992
The feasibility of a hyperfine spectroscopy on242mAm fission isomers has been demonstrated at the low target production rate of 10/s. The experimental method employed is based on resonance ionization spectroscopy in a buffer gas cell with detection of the ionization process by means of the fission decay of the isomers. The resonance ionization has been performed in two steps, utilizing an excimer dye laser combination with a repetition rate of 300 Hz. The first resonant step proceeds through theJ=7/2 term at 21440.35 cm−1, which has been excited with the tuncable dye laser beam of a wavelength of 466.28 nm, the second non-resonant step is achieved with the 351 nm radiation of the excimer la…
Radiation detected resonance ionization spectroscopy on208Tl and242fAm
1993
An ultra-sensitive laser spectroscopic method has been developed for the hyperfine spectroscopy of short-lived isotopes far off stability produced by heavy ion induced nuclear reactions at very weak intensity (> 1/s). It is based on resonance ionization spectroscopy in a buffer gas cell with radiation detection of the ionization process (RADRIS). As a first on-line application of RADRIS optical spectroscopy at242fAm fission isomers is in progress at the low target production rate of 10/s. The resonance ionization has been performed in two steps utilizing an excimer dye laser combination with a repetition rate of 300 Hz. The first resonant step proceeds through terms which correspond to wave…
The nature of the 4.8 eV optical absorption band induced by vacuum-ultraviolet irradiation of glassy SiO2
2000
Abstract The controversial optical absorption band centered at 4.8 eV, which is present in nearly all irradiated silicas, was investigated. It is caused by at least two different defects: non-bridging oxygen hole center (NBOHC) and interstitial ozone (O3). Both species have absorption bands at 4.8 eV, the O3-related band is identified by its susceptibility to bleaching by 4 to 5 eV photons, by a smaller halfwidth and by its independence from the NBOHC-associated 1.9 eV photoluminescence (PL) band. The contribution of NBOHC to the 4.8 eV band is dominant in most cases, while O3 is important in F2 excimer laser-irradiated samples of oxygen-rich glassy SiO2.
The behavior of interstitial oxygen atoms induced by F2 laser irradiation of oxygen-rich glassy SiO2
2002
Abstract Interstitial oxygen atoms in glassy silicon dioxide were created by photolysis of pre-existing interstitial oxygen molecules O 2 with a fluorine excimer laser (7.9 eV). The concentration of atomic oxygen interstitials was indirectly monitored by the disappearance and subsequent recovery of interstitial molecules which were monitored by their 1272 nm photoluminescence band. Most of the oxygen interstitials (>95%) are immobile at room temperature. The onset of their mobility occurs between 200 and 400 °C where around 95% of them recombine to form O 2 molecules. The high stability of interstitial oxygen atoms is consistent with the theoretical prediction that they are incorporated int…