Optical Spectral Measurements Research Articles

Study of chemiluminescence of methane–air flame stabilized on a flat porous burner

In this work, the spatial distribution and spectral characteristics of the chemiluminescence of chemically excited species, OH∗ and CH∗, are experimentally and numerically studied by using a stationary premixed methane–air flame stabilized on the surface of a flat porous burner for various equivalence ratio and normal pressure. Numerical simulations are carried out using detailed reaction mechanisms, and the experimental study includes high-resolution spatial and spectral optical measurements. Despite the data reported in the literature, it is found that (i) the rotational degrees of freedom of OH∗ and CH∗ are not in thermal equilibrium with the surrounding gas and therefore cannot be used to measure flame temperature; (ii) there is no direct correlation between the heat release rate and the distribution of OH∗ and CH∗; (iii) the detailed reaction mechanisms not only quantitatively, and also qualitatively differ in description of the OH∗ and CH∗ concentrations. Since the chemically excited species are well localized in a direction normal to the flame surface, they are demonstrated to be a very accurate markers of flame location. The shape of the combustion front can be reconstructed and resolved up to the accuracy of tens of microns, which is very important for estimation of blow-off critical parameters and measurement of the laminar burning velocity.Novelty and significance statementCurrently, there is a growing interest in the development of sensors for combustion control systems, including active control and suppression of instabilities, in combustion chambers of various devices and engines based on chemiluminescence of excited reaction species. The possibility of non-invasive determination of parameters such as flame temperature, stoichiometry, heat release rate location, etc. using this technique is discussed. We have found that most of these parameters cannot be estimated either due to fundamental limitations or insufficient knowledge of the reaction kinetics involved in the production of these species. Nevertheless, since OH* and CH* are well localized in the direction normal to the flame surface, they can be used as very accurate markers of flame shape and position, allowing us to reconstruct the flame surface to within tens of microns resolution, which is very important for estimating blow-off critical parameters and measuring laminar burning velocity.

First principles insight into the study of the structural, stability, and optoelectronic properties of alkali-based single halide perovskite ZSnCl3 (Z = Na/K) materials for photovoltaic applications.

Metal halide perovskites are crystalline materials with a sharp increase in popularity and rapidly becoming a major contender for optoelectronic device applications. In this work, we provide the optoelectronic features of a possible novel candidate, ZSnCl3 (Z = Na/K) Sn-based on a detailed numerical simulation. The output of the current computations is compared to the results that are currently available, and a respectable agreement is noted. The studied compounds were cubic in nature and structurally stabe. The mechanical properties reflectthe mechanical stability and ductility of the proposed materials. The Sn-based single perovskite compounds proposed in this study are mechanically stable and ductile. The narrow direct band gap for NaSnCl3 and KSnCl3 are 1.36 eV and 1.47 eV, respectively, using the HSE06 hybrid function with the Boltztrp2 integrated in Quantum ESPRESSO (QE) software. The effective use of these compounds in perovskite solar cells and other optoelectronic applications was confirmed by optical absorption spectral measurements conducted in the photon energy range of 0-20 eV.

EMU/GAMA: Radio detected galaxies are more obscured than optically selected galaxies

Abstract We demonstrate the importance of radio selection in probing heavily obscured galaxy populations. We combine Evolutionary Map of the Universe (EMU) Early Science data in the Galaxy and Mass Assembly (GAMA) G23 field with the GAMA data, providing optical photometry and spectral line measurements, together withWide-field Infrared Survey Explorer (WISE) infrared (IR) photometry, providing IR luminosities and colours. We investigate the degree of obscuration in star forming galaxies, based on the Balmer decrement (BD), and explore how this trend varies, over a redshift range of 0 < z < 0.345. We demonstrate that the radio detected population has on average higher levels of obscuration than the parent optical sample, arising through missing the lowest BD and lowest mass galaxies, which are also the lower star formation rate (SFR) and metallicity systems. We discuss possible explanations for this result, including speculation around whether it might arise from steeper stellar initial mass functions in low mass, low SFR galaxies.

Optical spectra of EGFR inhibitor AG-1478 for benchmarking DFT functionals

Optical spectroscopy (UV–vis and fluorescence spectroscopy) is sensitive to the chemical environment and conformation of fluorophores and therefore, serves as an ideal probe for the conformation and solvent responses. Tyrosine kinase inhibitors (TKI) such as AG-1478 of epidermal growth factor receptor when containing a quinazolinamine scaffold are fluorophores. It is, however, very important to benchmark density functional theory (DFT) method against optical spectral measurements, when time-dependent DFT is applied. In this study, the performance of up to 22 DFT functionals is benchmarked with respect to the measured optical spectra of AG-1478 in dimethyl sulfoxide (DMSO) solvent. It is discovered when combined with the 6–311++G(d, p) basis set, there are top seven functionals; B3PW91, B3LYP, B3P86, PBE1PBE, APFD, HSEH1PBE, and N12SX DFT-VXC functionals are identified as the top performers. Becke’s three-parameter exchange functional (B3) tends to generate accurate optical spectra to form the best three functionals, B3LYP, B3PW91 and B3P86. Specifically, B3PW91 was recommended for studying the optical properties of 4-quinazolinamine TKIs, B3LYP was found to be excellent for absorption spectrum, while B3P86 was identified as the best for emission spectrum. Any further corrections to B3LYP, such as CAM-B3LYP, LC-B3LYP, and B3LYP-D3 result in larger errors in the optical spectra of AG-1478 in DMSO solvent. These best three (B3Vc) functionals are reliable tools for optical properties of the TKIs and therefore the design of new agents with larger Stokes shift for medical image applications. To obtain reliable optical spectra for this class of 4-quinazolinamine based TKIs, it is important to include the electron correlation energy.

Shedding New Light on Weak Emission-line Quasars in the C iv–Hβ Parameter Space

Weak emission-line quasars (WLQs) are a subset of type 1 quasars that exhibit extremely weak Lyα + N v λ1240 and/or C iv λ1549 emission lines. We investigate the relationship between emission-line properties and accretion rate for a sample of 230 “ordinary” type 1 quasars and 18 WLQs at z < 0.5 and 1.5 < z < 3.5 that have rest-frame ultraviolet and optical spectral measurements. We apply a correction to the Hβ-based black hole mass (M BH) estimates of these quasars using the strength of the optical Fe ii emission. We confirm previous findings that WLQs’ M BH values are overestimated by up to an order of magnitude using the traditional broad-emission-line region size–luminosity relation. With this M BH correction, we find a significant correlation between Hβ-based Eddington luminosity ratios and a combination of the rest-frame C iv equivalent width and C iv blueshift with respect to the systemic redshift. This correlation holds for both ordinary quasars and WLQs, which suggests that the two-dimensional C iv parameter space can serve as an indicator of accretion rate in all type 1 quasars across a wide range of spectral properties.

Behavior of bismuth ions in the two glassy systems of 50 LiF-50 P2O5 and 50 LiF-50 B2O3 (mol %) assessed by optical, FTIR and photoluminescence spectra in addition to thermal expansion properties

Glasses from two varieties of (LiF-B2O3) and (LiF-P2O5) systems with equal 50 mol % for each partner together with samples doped with 1 or 2% Bi2O3 were synthesized by melting–annealing mechanism. Multiple optical, FTIR and photoluminescence spectral measurements were carried out. Optical spectra of Bi2O3—doped glasses exhibit UV-near visible peaks owing to the specific absorption of Bi3+ ions. FTIR spectra elucidate the presence of characteristic vibrational bands from (LiF-B2O3) glass due to (BO3) and (BO3F) groups beside (LiF4) groups while the fluorophosphate glasses (LiF-P2O5) show vibrations due to PO4 and (PO3F) groups and also the possible sharing of (LiF4) groups. Photoluminescence spectral data reveal extended emission from about 375 to 700 nm and is more prominent in (LiF-B2O3) system than (LiF-P2O5) system. The thermal expansion data reveal similar behavior and the derived transition and softening temperatures are slightly lower in (LiF-P2O5) glasses than (LiF-B2O3) glasses.

BASS. XXIV. The BASS DR2 Spectroscopic Line Measurements and AGN Demographics

We present the second catalog and data release of optical spectral line measurements and active galactic nucleus (AGN) demographics of the BAT AGN Spectroscopic Survey, which focuses on the Swift-BAT hard X-ray detected AGNs. We use spectra from dedicated campaigns and publicly available archives to investigate spectral properties of most of the AGNs listed in the 70 month Swift-BAT all-sky catalog; specifically, 743 of the 746 unbeamed and unlensed AGNs (99.6%). We find a good correspondence between the optical emission line widths and the hydrogen column density distributions using the X-ray spectra, with a clear dichotomy of AGN types for N H = 1022 cm−2. Based on optical emission-line diagnostics, we show that 48%–75% of BAT AGNs are classified as Seyfert, depending on the choice of emission lines used in the diagnostics. The fraction of objects with upper limits on line emission varies from 6% to 20%. Roughly 4% of the BAT AGNs have lines too weak to be placed on the most commonly used diagnostic diagram, [O iii]λ5007/Hβ versus [N ii]λ6584/Hα, despite the high signal-to-noise ratio of their spectra. This value increases to 35% in the [O iii]λ5007/[O ii]λ3727 diagram, owing to difficulties in line detection. Compared to optically selected narrow-line AGNs in the Sloan Digital Sky Survey, the BAT narrow-line AGNs have a higher rate of reddening/extinction, with Hα/Hβ > 5 (∼36%), indicating that hard X-ray selection more effectively detects obscured AGNs from the underlying AGN population. Finally, we present a subpopulation of AGNs that feature complex broad lines (34%, 250/743) or double-peaked narrow emission lines (2%, 17/743).

Preparation and characterization of glasses from the binary sodium fluoroborate system NaF–B2O3 within the range (10–50 mol% NaF) assessed by structural FTIR, optical and thermal properties and effects of gamma irradiation

Extended glasses from the binary system (NaF-B2O3) with (10→50 mol% NaF) were synthesized by the traditional melting-annealing route. These unfamiliar glasses with high extended NaF contents than Na2O were characterized by multi-techniques including optical and FTIR spectral analysis beside measurements of their thermal expansion parameters. The optical (UV–visible) spectra of the glasses reveal obvious transparency except for the appearance of distinct UV absorption due to unavoidable trace ferric ions impurities present within the laboratory chemicals. Structural FTIR spectra indicate that NaF primarily acts the same as Na2O progressively converting some of the BO3 units to produce tetrahedral (BO3F) units and then at a high percent of NaF is assumed to form additional (NaF4) groups and hence the intensity of the bands within the range 800–1200 cm−1 due to combined tetrahedral groups (BO4 + NaF4) is always higher than that for the peaks at the range 1200–1600 cm−1due to vibrational BO3 groups. The thermal expansion data reveal that the dilatometric softening temperature primarily increases due to the formation of compact tetrahedral (BO3F) groups. It is obvious that this unfamiliar (NaF–B2O3) glass does not show an anomalous behavior as that reported for (Na2O–B2O3) glassy system and other alkali-B2O3 glasses in their thermal expansion properties. Gamma irradiation did not show any distinct variations in the FTIR spectra indicating the stability of the structural building groups in this NaF–B2O3 glass system. On the other hand, the optical spectra show the displacement of one of the two broad bands in the UV spectra which is assumed to be due to a photochemical reaction between some Fe3+ ions present as trace impurities and formed freed electrons during the irradiation process.

Influence of RE (Pr3+, Er3+, Nd3+) doping on structural, vibrational and enhanced persistent photocatalytic properties of ZnO nanostructures

Rare earth (RE- Pr, Er and Nd) doped ZnO nanostructures were prepared through simple wet chemical precipitation route. The RE doping induced interesting morphological transition from spherical to flower like structures were analyzed. The X-ray diffraction (XRD) measurements revealed that the prepared materials were of highly crystalline in nature and RE dopant ions did not altered the crystal structure of ZnO. The microstrain of ZnO was altered with respect to the nature of dopants. In the case of the Pr doped ZnO, X-ray photoelectron spectroscopy (XPS) analysis confirmed that the dopant (Pr) ions successfully substituted in the ZnO lattice. Raman spectra revealed RE doping induced lower energy side shift and variation in intensity of the peaks related to the characteristic phonon modes of ZnO. In the case of Nd doped ZnO nanostructures, dopant induced suppression in classical Raman modes and evolution of multiphonon related modes were identified. Optical diffuse reflectance spectral (DRS) measurements, along with the characteristic excitonic band of ZnO, other bands associated to the transitions of 4f energy levels related to the RE ions were observed. The partially filled 4f orbitals led to the enhanced photocatalytic activity in RE doped ZnO nanostructures. The observed enhanced photocatalytic activity in RE doped ZnO when compared to bare ZnO was discussed. The decolorization efficiency of MB ensued the following order 96 > 94 > 86 > 78% for ZnErO, ZnNdO, ZnPrO and ZnO, respectively.

Comparative shielding behavior of binary PbO-B2O3 and Bi2O3-B2O3 glasses with high heavy metal oxide contents towards gamma irradiation revealed by collective optical, FTIR and ESR measurements

Selected glasses with high percent of heavy metal oxides (60-85 mol%) from the two binary systems (PbO-B2O3) and (Bi2O3-B2O3) were prepared. Collective characterization of the prepared glasses was carried out through optical, FTIR and ESR spectral measurements before and after gamma irradiation. Optical absorption data of these glasses indicate the appearance of distinct UV absorption bands which are related to unavoidable contaminated trace iron impurities (Fe3+ ions) together with the presence of absorption due to Pb2+ or Bi3+ ions. Gamma irradiation causes some obvious variations in the UV spectra of the lead borate glasses but the bismuth borate glasses are more stable. FTIR spectral measurements reveal the appearance of vibrational bands due to triangular BO3 and tetrahedral BO4 groups within their different characteristic wavenumbers. The deconvoluted IR spectra refer to the interfering vibrational bands due to PbO4, BiO3, BiO6 groups beside the presence of the two highly distinguish differently coordinated borate groups (BO3, BO4). The effects of gamma irradiation on the FTIR spectra are limited on lead borate glasses and bismuth borate glasses but are more noticed in the equalization of the intensities of both the vibrations due to tetrahedral and triangular borate groups due to the light weight of the boron element which shows response in triangular groups but less effect in compact tetrahedral borate groups. Also, the near-IR bands due to vibrations of OH, water are observed to decrease dut to their loose bonding in the network.ESR data indicate the stabilization upon irradiation of Bi2O3-B2O3 glass while the PbO-B2O3 show small changes.

Role of silver ions in Na2O-CaF2-P2O5 host glass and its corresponding glass-ceramic: Searching for antibacterial behavior-supplemented by spectral, optical, FTIR and SEM investigations

Glasses based on the base host Na2O-CaF2-P2O5 system with increasing Ag2O as additives or loading (0.2 to 1 wt%) were prepared by melting-annealing technique. Multiple characterizations of the prepared glasses were carried out. Heat- treatment of the glasses was done through a two-step protocol to convert them to their corresponding glass-ceramics derivatives. The state of silver ions was analyzed by additional optical and FTIR spectral beside SEM measurements. Antibacterial behavior of the Ag2+ ions in the studied glasses and their glass-ceramic derivatives was conducted by their response towards two G+ve strains (Staphylococcus aureus, Bacillus cereus), one G-ve bacterial strain (Escherichia coli), one yeast (Candida albicans) and one fungi (Aspergillus niger). Optical spectra show distinct UV absorption in the undoped glass spectrum and extend to near visible with increasing Ag2O content. This distinct UV absorption is assumed to originate from unavoidable trace iron (Fe3+) impurities while the peak at 420 nm is related to nanocrystalline (Ag0)n . FTIR spectra show vibrational spectra within the mid region 400-1650 cm-1 which are characteristic for phosphate (PO4) groups with some suggested (PO3F) groups. The dopant silver ions show no distinct effect on the FTIR spectra. After immersion in phosphate solution FTIR spectra of the glass-ceramic reveal the formation of hydroxyapatite layer. X-ray diffraction results indicate the formation of crystalline phosphate phases for the undoped glass-ceramic. Two silver crystalline phases are identified after addition of Ag2+ ions. SEM images confirm the formation of apatite layer with different additions of silver ion. The antibacterial analysis also indicate the promising effect of the glass-ceramics than their parent glass in the bioactivity applications.

CORONENE ORGANIC FILMS: OPTICAL AND SPECTRAL CHARACTERISTICS UNDER ANNEALING TEMPERATURE INFLUENCES

In this study, spin coating, which is a chemical film layer thin film deposition method, was used for coronene films that were grown on Si substrates annealed at 325, 350 and 375[Formula: see text]K to examine the impacts on the optical properties of films. This method allows for easy control of the deposition parameters such as concentration, temperature and time as well as enables the film growth at low cost. Optical (UV–Vis) spectral measurements in the wavelength range from 200[Formula: see text]nm to 800[Formula: see text]nm were used to extract the bandgap information and to calculate various optical parameters of the spin-coated coronene films. The electronic transitions on the absorption of photons of suitable energy are of indirect allowed type. The corresponding optical bandgap ([Formula: see text]) was determined. Complex dielectric constants, dissipation factor, optical and electrical conductances and refractive index of coronene films were analyzed as a function of temperature. As the film annealing temperature was increased, the dielectric constants and the refractive index values increased, whereas the optical bandgap and electrical and optical conductivity values decreased.

Optical Spectral Tools for Diagnosing Water Media Quality: A Case Study on the Angara/Yenisey River System in the Siberian Region

This paper presents the results of spectral optical measurements of hydrochemical characteristics in the Angara/Yenisei river system (AYRS) extending from Lake Baikal to the estuary of the Yenisei River. For the first time, such large-scale observations were made as part of a joint American-Russian expedition in July and August of 1995, when concentrations of radionuclides, heavy metals, and oil hydrocarbons were assessed. The results of this study were obtained as part of the Russian hydrochemical expedition in July and August, 2019. For in situ measurements and sampling at 14 sampling sites, three optical spectral instruments and appropriate software were used, including big data processing algorithms and an AYRS simulation model. The results show that the water quality in AYRS has improved slightly due to the reasonably reduced anthropogenic industrial impact. Chemical concentrations in water have been found to vary along the Angara River depending on the location of the dams. The results of in situ measurements and modeling evaluations are given. To overcome the uncertainties in the data caused by the large monitoring area, it is recommended to use the combined AYRS simulation model and the universal 8-channel spectrophotometer installed on a fixed platform for continuous monitoring.

The Advance of Plasmonic-Electric Nanopipette Sensing in Single Cells

Nanopipette provides a promising limited space, which demonstrates achievements in optical, electrochemical, and mass spectral measurements on the nanoscales. It has been applied to uncover the potential properties of populations and dynamics of individual molecules and individual particles. Plasmonic-electric nanopipette tip probe of individual cells provides more accurate diacrisis and grasp of elementary chemical and biological processes. Recent advances in individual cells provide tools for hypersensitive analysis. In this review, we summarize the results of recent progresses in studying nanopipette photonic and electrical probe tips of individual cells. The benefits of confining these optical-electric nanopipette tip probe to a compatible dimension measurement interface are instantiated. Ultimately, the opportunities and challenges of optical-electric nanopipette tip probe of single cell are addressed.

Concentration dependent neodymium doped oxy fluoroborate glasses for 1.08 μm laser applications

Different concentrations of neodymium-doped (Nd3+ ions) Oxy Fluoroborate (OFB) glasses were fabricated and systematically analyzed by employing spectroscopic techniques such as optical absorption, photoluminescence (PL) and PL decay spectral measurements to understand the NIR lasing potentialities. The information pertaining to absorption spectral features were subjected to Judd-Ofelt (J-O) analysis to understand the radiative properties such as transition probability (AR), radiative lifetime (τR) and branching ratios (βR) possessed by the as prepared Nd3+ ions doped OFB glasses. By correlating the radiative properties with the emission and PL decay spectral profiles, the emission cross-sections (σse) and quantum efficiency values are evaluated for the prominent fluorescent levels of Nd3+ ions in the as prepared glasses. Under 808 nm diode laser excitation, all the OFB glasses under investigation showcased two prominent NIR emissions at 1085 nm (4F3/2 → 4I11/2) and 1328 nm (4F3/2 → 4I13/2). The intensities of both the emission peaks escalates with increases in Nd3+ ions concentration up to 1 mol% and beyond decreases showcasing concentration quenching. The experimental lifetime values estimated from the single exponential PL decay profiles of 4F3/2 level are decreasing monotonously with increase in Nd3+ ions concentration in the as prepared OFB glasses. Relatively higher branching ratios, emission cross-sections and quantum efficiency values estimated for Nd3+ ions doped OFB glasses indicates the potential usage of the as prepared glasses for 1.08 μm laser applications.

Non-destructive thickness characterisation of 3D multilayer semiconductor devices using optical spectral measurements and machine learning

Three-dimensional (3D) semiconductor devices can address the limitations of traditional two-dimensional (2D) devices by expanding the integration space in the vertical direction. A 3D NOT-AND (NAND) flash memory device is presently the most commercially successful 3D semiconductor device. It vertically stacks more than 100 semiconductor material layers to provide more storage capacity and better energy efficiency than 2D NAND flash memory devices. In the manufacturing of 3D NAND, accurate characterisation of layer-by-layer thickness is critical to prevent the production of defective devices due to non-uniformly deposited layers. To date, electron microscopes have been used in production facilities to characterise multilayer semiconductor devices by imaging cross-sections of samples. However, this approach is not suitable for total inspection because of the wafer-cutting procedure. Here, we propose a non-destructive method for thickness characterisation of multilayer semiconductor devices using optical spectral measurements and machine learning. For > 200-layer oxide/nitride multilayer stacks, we show that each layer thickness can be non-destructively determined with an average of approximately 1.6 Å root-mean-square error. We also develop outlier detection models that can correctly classify normal and outlier devices. This is an important step towards the total inspection of ultra-high-density 3D NAND flash memory devices. It is expected to have a significant impact on the manufacturing of various multilayer and 3D devices.

Strain-induced hierarchical ripples in MoS2 layers investigated by atomic force microscopy

Strain engineering plays a vital role in controlling the physical properties of two-dimensional (2D) materials. However, the nanomechanical behavior of atomically thin 2D crystals under strain has not been completely understood. Here, strain-induced hierarchical ripple nanostructures in triangular MoS2 flakes were investigated by advanced atomic force microscopy and optical spectral measurements. The hierarchical nanoripples exhibited a threefold radial pattern, and their mechanical, electronic, and optical spectra characteristics were significantly modified due to the suffering from large tensile strain. Structure evolution of these hierarchical nanoripples was further discussed based on the geometry and thickness of MoS2 flakes, and we attributed the curtain effect at the limit of a single atomic layer. Our study will be beneficial in designing nanomechanical structures and prototype electromechanical devices with 2D materials.

Multi-wavelength observations of the BL Lac object Fermi J1544-0649: One year after its awakening

We report observations of a transient source FermiJ1544-0649 from radio to γ-rays. FermiJ1544-0649 was discovered by the Fermi-LAT in May 2017. Follow-up Swift-XRT observations revealed three flaring episodes through March 2018, and the peak X-ray flux is about 103 higher than the ROSAT all-sky survey (RASS) flux upper limit. Optical spectral measurements taken by the Magellan 6.5-m telescope and the Lick-Shane telescope both show a largely featureless spectrum, strengthening the BL Lac interpretation first proposed by Bruni et al. (2018). The optical and mid-infrared (MIR) emission goes to a higher state in 2018, when the flux in high energies goes down to a lower level. Our RATAN-600 m measurements at 4.8 GHz and 8.2 GHz do not indicate any significant radio flux variation over the monitoring seasons in 2017 and 2018, nor deviate from the archival NVSS flux level. During GeV flaring times, the spectrum is very hard (Γγ∼1.7) in the GeV band and at times also very hard ((ΓX≲2) in the X-rays, similar to a high-synchrotron-peak (or even an extreme) BL Lac object, making FermiJ1544-0649 a good target for ground-based Cherenkov telescopes.

Non-destructive thickness characterisation of 3D multilayer semiconductor devices using optical spectral measurements and machine learning

Non-destructive thickness characterisation of 3D multilayer semiconductor devices using optical spectral measurements and machine learning

Vanadium structural role in binary fluoride borate glasses and effects of gamma irradiation

Three binary fluoroborate glasses from the systems LiF–B2O3, NaF–B2O3 and CaF2–B2O3 (50 mol% each) together with V2O5-doped derived samples from the same three systems were prepared. Collective optical, FTIR and ESR spectral measurements were carried out before and after gamma irradiation (6 M rad dose). FTIR spectra of the studied glasses reveal mostly repetitive vibrational curves with limited variations. The IR spectra show condensed vibrations due to both triangular (BO3) and tetrahedral coordinated fluoro-borate groups (BO3F) in their distinct and characteristic wavenumbers similar to that obtained from Li2O–B2O3, Na2O–B2O3 and CaO–B2O3 glasses. Gamma irradiation causes limited increase of the UV absorption within the optical spectra of undoped glasses and the generation of an induced small curvature in the visible. This behavior is related to some photochemical effects and the formation of (BOHC) or (NBOHC) or even similar fluoride analogues. The V2O5-doped glasses show some shielding behavior towards gamma irradiation and the spectral curves remain almost unaffected.ESR spectra show distinct signals for the undoped glass correlated with trace ferric oxide impurity. The V2O5-doped glasses before irradiation reveal three small signals indicating that the vanadium ions exist in V5+ with no unpaired electron and the few percent of low valence (V3+, V4+) ions producing the identified small signals. Gamma irradiation decreases the intensities of the small signals due to lower valence vanadium ions but causes the splitting of the main signals for the undoped and V2O5 doped samples. The calculated N4 values are correlated with both ability of V2O5 to promote more (BO4) or (BO3F) units and the variations are correlated with housing behavior of LiF and NaF as modifiers while CaF2 which can form some (CaF4) units.