Fundamental defect centers in glass: Electron spin resonance and optical absorption studies of irradiated phosphorus-doped silica glass and optical fibers

Abstract

A magnifying fiber element with an array of sub-wavelength Ge/ZnSe pixel waveguides for infrared imaging Appl. Phys. Lett. 101, 021108 (2012) Embedded calibration system for the DIII-D Langmuir probe analog fiber optic links Rev. Sci. Instrum. 83, 10D710 (2012) Analytical analysis of modulation instability in fiber optics AIP Advances 2, 022168 (2012) Atmospheric pressure dielectric barrier microplasmas inside hollow-core optical fibers Defect centers induced by ionizing radiation (50-100-keY x rays, 6OCo r rays) in high purity Pdoped silica glass have been observed and elucidated by ESR spectroscopy. Four generic species are well characterized on the basis of the observed 31p hyperfine splittings and g values as defects analogous to PO; -(phosphoryl), PO! -(phosphoranyl), PO~ -(phosphinyl), and PO! -radicals. The latter species, also termed the phosphorus-oxygen-hole center (POHC), is shown to occur in two variants comprising holes trapped on one or two nonbridging oxygens. Radiation-induced Si E ' centers with and without P next-nearest-neighbors were also identified, and a singlet resonance S due to E; type defects such as (OSi 2 )Si· and/or (02Si)Si. was observed to grow in with annealing above -800 K, regardless of whether or not the sample was irradiated. The structures, formation mechanisms, and precursors of these defects have been determined or inferred for all centers. Radiation-induced optical absorption spectra over the range 0.5-6.2 eY have been obtained for bulk glass and fiber samples after irradiation and following anneals to various temperatures up to 1250 K. Gaussian resolutions of the spectra into component bands have been performed and isochronal anneal data have been used to identify optical absorptions of the PO; -, PO! -, PO~ -, POHC, and S centers. The PO; -defect was found to absorb at -0.8 eY in the region of interest for fiber optic communication. Oscillator strengths are calculated for all bands.

Luminescence of phosphorus containing oxide materials: Crystalline SiO2‐P and 3P2O5⋅7SiO2; CaO⋅P2O5; SrO⋅P2O5 glasses

“…Given in Fig.14 signal growth on irradiation time are presented also in Fig.12 . The ESR signal well corresponds to previously studied in [8][9][10] phosphorus related centers POHC. Unfortunately we were not able obtain P(I) and P(II) signal perhaps due to insufficient ability of our spectrometer.…”

“…The doubly degenerate P(II) excited state has no such symmetry. Other detected defects are the P-non-bridging-oxygen hole centers (POHCs) with hfs splittings ~25 to 50 G. Silica glass doped with phosphorus was studied by ESR [10]. Four main centers detected were P 1 , P 2 , P 3 and Phosphorus Oxygen Hole Center (POHC).…”

Characterization of defects in waveguides formed by electron irradiation of silica-on-silicon

“…Recently, however, it has been linked with absorption at 630 nm in irradiated bulk silica and is therefore also likely to be caused by NBOHC defects [26]. In phosphorus doped silica, it has also been linked with the phosphorus oxygen center, or POHC, defect [27].…”

Formation and assignment of silver defect centres in phosphate glass induced by femtosecond laser pulses

“…Moreover, the absorption band at 273 nm (Curve 4) corresponds to absorption of oxygen-related hole centres of unknown structure (OHC). Broad absorption band at 440 nm (Curve 5), termed the phosphorus-oxygen-hole-center (POHC), is due to one or two non-bridging oxygen of a PO 4 unit trapping a hole (Griscom et al, 1983). Fig.…”