Amaranath Govindolla

@bits-pilani.ac.in

Assistant Professor, Department of General Sciences (Physics)
Birla Institute of Technology and Science, Pilani, Dubai Campus

Amaranath Govindolla


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https://researchid.co/amargovi4

RESEARCH INTERESTS

Laser materials
Photonics
Spectroscopy
9

Scopus Publications

180

Scholar Citations

6

Scholar h-index

6

Scholar i10-index

Scopus Publications

  • Fluorescence spectral properties of Sm3 +- and Dy3 +-doped laser liquids
    N. Sooraj Hussain, K. Annapurna, D.V. Vasantha Rao, K. Rajamohan Reddy, G. Amaranath, et al.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy, 1997
    This brief note reports the fluorescence characteristics of the measured emission transitions of Sm 3+ - and Dy 3+ -doped (SeOCl 2 + SnCl 4 ) laser liquids, by the application of the Judd-Ofelt intensity factors obtained from their absorption spectral profiles.
  • Nonlinearity and elastic properties of Cr(3+):Al2O3 and Ti(3+):Al2O3 laser crystals
    G. Amaranath, S. Buddhudu, A. Mandelis
    Solid State Communications, 1994
    This paper reports the nonlinearity properties such as abbe-number (ν), nonlinear refractive index ( n 2 ), nonlinearity refractive index coefficient (γ) and certain elastic properties of bulk, shear modulus, Poisson's ratio for the Cr(3+):Al 2 O 3 and Ti(3+):Al 2 O 3 laser crystals. Radiational influences from the Ar + laser and the UV sources on these materials, have also been studied.
  • Photoluminescence spectra of er3+ - doped fluorophosphate glasses
    A. V. RANGA Reddy, K. Annapurna, G. Amaranath, A. S. Jacob, A KUMAR Suresh, et al.
    Ferroelectrics Letters Section, 1992
    This short paper reports various physical, absorption and emission properties of the Er3+-doped glasses based on the (NaPO3)6 as the major constituent by changing the cations (Li, Na & K) both in mixed and unmixed forms. The obtained results show that the optical properties are found interesting in glass-B which contains, 20M% NRF as the network modifier.
  • Optical properties of rare-earth-doped HMF glasses
    G. Amaranath, S. Buddhudu
    Journal of Non Crystalline Solids, 1992
    Physical, optical properties and emission characteristics of heavy metal fluoride (HMF) glasses containing 1 mol% of Pr, Nd and Tb as dopants are reported. Room temperature absorption spectra have been determined from VIS to the NIR. Photoluminescence spectra were recorded at 300 and 77 K to measure the stimulated emission cross-section of the laser transitions employing an Ar + (487.9 nm) laser. The quantum efficiencies of the fluorescent levels of these optical glasses were determined from measured lifetimes of the recorded luminescent levels at room and liquid nitrogen temperatures.
  • Spectroscopic properties of Nd3+ -doped heavy metal fluoride glasses
    G. Amaranath, S. Buddhudu, F.J. Bryant, Luo Xi, B. Yu, et al.
    Journal of Luminescence, 1991
    Indium trifluoride based multicomponent glasses of the composition: 30InF3-30BaF2-10ThF4-9ZnF2-20RF, (RF = LiF, NaF and KF) with Nd3+ (1 M%) were prepared and an investigation was carried out on the significant effects of RF on the physical properties, the absorption spectra, the photoluminescence spectra and the decay times (μs) of the laser emission transition 4 F 3 2 → 4 I 11 2 (1.05 μm) at 300 and 77 K, by using an argon ion laser as the source of excitation. To understand the laser efficiency of these materials, the values of the spectroscopic quality factor (ω4/ω6) and the quantum efficiency (ƞ) obtained from the measured and computed lifetimes of the 4 F 3 2 → 4 I 11 2 have been estimated and it is found that glass A could be suggested as a suitable lasing material.
  • Luminescence properties of Nd3+ in mixed alkali flouride glasses
    G. Amaranath, S. Buddhudu, F.J. Bryant, Luo Xi, B. Yu, et al.
    Journal of Luminescence, 1991
    Three indium triflouride based neodymium glasses (abbreviated as A, B and C) with the mixed dual alkali flourides as network modifiers have been newly prepared to characterize their absorption and photoluminescence spectra, both at room and liquid nitrogen temperature. By performing a least squares fit analysis, the Judd-Ofelt parameters and the spectroscopic quality factor (Ω4/Ω6) have been computed from the absorption levels. The Judd-Ofelt parameters (Ωλ) have been used to derive the radiative properties of these glasses in the determination of the predicted radiative lifetime of the measured excited state. The recorded low temperature photoluminescence spectra have revealed an intense emission peak 4 F 3 2 a 4 I 1 2 at λ = 1.05 μm and for this level, the lifetime has been measured by the use of an Ar+ ion laser. The flourescence characteristics of these mixed alkali flouride glasses have been compared with the results obtained on the Nd-glasses possessing the individual alkali flourides as the modifiers.
  • Spectroscopic properties of Tb3+-doped fluoride glasses
    G Amaranath, S Buddhudu, F.J Bryant
    Journal of Non Crystalline Solids, 1990
    In this paper, the preparation is reported of a new family of Tb-doped fluoride glasses with the following composition: 30BaF2 + 30InF3 + 10ThF4 + 9ZnF2 + 20RF (where RF = LiF, NaF and KF). These glasses have been used for a systematic study on the optical absorption, excitation and photoluminescence spectral properties from the near UV to the NIR. On the basis of the measured values of densities and refractive indices, the dielectric constant, reflection losses, molar-refraction, Tb3+ ion concentration in glasses, and several other physical properties were determined. From the measured absorption spectral intensities of five different states, the validity of the Judd-Ofelt model was examined in the evaluation of the intensities, transition probabilities, relaxation rates and radiative lifetime of the 5D4 luminescent level. The lifetime of the 5 D 4 → 7 F j fluorescence was examined at both 300 K and 77 K and it was found it compared well with the theoretical value. The effects of the alkali cation change on the induced emission cross-section, quantum efficiency and branching ratios of this luminescent level based on the measured and computed fluorescence lifetimes were also studied.
  • Spectroscopic properties of pr3+-doped multicomponent fluoride glasses
    G. Amaranath, S. Buddhudu, F.J. Bryant, Luo Xi, B. Yu, et al.
    Materials Research Bulletin, 1990
    A new family of five optical glasses of the following chemical composition with 1M% PrF 3 were prepared to examine the effects of alkali fluorides both in mixed and unmixed form: 30InF 3 /1b30BaF 2 /1b10ThF 4 /1b9ZnF 2 /1b20RF, where RF=LiF, NaF, KF, NaF/1bKF and KF/1bLiF. Significant results have been obtained from the physical characterization of the fluoride glasses. Both the absorption and photoluminescence spectra of these glasses were also measured. Laser emission properties of these glasses were examined both at room and liquid nitrogen temperatures by using an Ar + ion laser. The fluorescent lifetime (in μs) of the emission state 1 D 2 → 3 H 4 ( λ =0.59 μ m) was measured at both 300 K and 77 K. The stimulated emission cross-section of different observed luminescent states of these Pr-doped glasses were measured by the use of Judd-Ofelt theory with the recorded photoluminescence spectra.
  • Emission properties of Tb3+-doped alkali mixed fluoride glasses
    G. Amaranath, S. Buddhudu, F.J. Bryant
    Solid State Communications, 1989
    This short note brings out the results on the various physical and fluorescence properties of Tb3+-doped glasses of the chemical composition of 30BaF2 + 30InF3 + 10ThF4 + 9ZnF2 + 20RF, where the RF is LiF−NaF, NaF−KF and the KF−LiF pairs. The magnitude of the quantum efficiency of the flourescent level 5D4 → 7F6 describes the suitability of the Judd-Ofelt theory in characterising the laser-emission properties from the measurements of decaytimes of luminescent state at 300 K and 77 K using the argon ion laser.

RECENT SCHOLAR PUBLICATIONS

  • Fluorescence spectral properties of Sm3+-and Dy3+-doped laser liquids
    NS Hussain, K Annapurna, DVV Rao, KR Reddy, G Amaranath, ...
    Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 53 (5 … , 1997
    1997
    Citations: 5
  • Nonlinearity and elastic properties of Cr (3+): Al2O3 and Ti (3+): Al2O3 laser crystals
    G Amaranath, S Buddhudu, A Mandelis
    Solid state communications 91 (9), 761-763 , 1994
    1994
    Citations: 1
  • Photoluminescence spectra of Er 3+ -doped fluorophosphate glasses
    AVR Reddy, K Annapurna, G Amaranath, AS Jacob, AK Suresh, ...
    Ferroelectrics Letters Section 14 (5-6), 145-159 , 1992
    1992
    Citations: 4
  • Optical properties of rare-earth-doped HMF glasses
    G Amaranath, S Buddhudu
    Journal of non-crystalline solids 143, 252-256 , 1992
    1992
    Citations: 27
  • Luminescence properties of Nd3+ in mixed alkali flouride glasses
    G Amaranath, S Buddhudu, FJ Bryant, L Xi, B Yu, S Huang
    Journal of luminescence 50 (1), 17-20 , 1991
    1991
    Citations: 16
  • Optical Properties of Ho(NO 3 ) 3 6H 2 O: Organic Acid Complexes
    S Buddhudu, VN Rangarajan, G Amaranath, R Harinath, AS Kumar
    Physics and Chemistry of Liquids 23 (2), 61-68 , 1991
    1991
    Citations: 2
  • Spectroscopic properties of Nd3+-doped heavy metal fluoride glasses
    G Amaranath, S Buddhudu, FJ Bryant, L Xi, B Yu, S Huang
    Journal of luminescence 47 (5), 255-260 , 1991
    1991
    Citations: 18
  • Optical Absorption And Luminescence Properties Of Certain Rare Earths Doped Heavy Metal Fluoride Glasses
    G Amaranath
    1991
  • Spectroscopic properties of Pr3+-doped multicomponent fluoride glasses
    G Amaranath, S Buddhudu, FJ Bryant, L Xi, B Yu, S Huang
    Materials research bulletin 25 (10), 1317-1323 , 1990
    1990
    Citations: 31
  • Spectroscopic properties of Tb3+-doped fluoride glasses
    G Amaranath, S Buddhudu, FJ Bryant
    Journal of non-crystalline solids 122 (1), 66-73 , 1990
    1990
    Citations: 59
  • AbuHadba, N. and CR Aita, Growth and near-ultraviolet optical absorption char-acteristics of sputter deposited nominal germania Aita, CR, see AbuHadba
    G Amaranath, S Buddhudu, FJ Bryant, MA Aysawy, A Szasz, L Kertesz, ...
    Journal of Non-Crystalline Solids 122, 319-321 , 1990
    1990
  • Emission properties of Tb3+-doped alkali mixed fluoride glasses
    G Amaranath, S Buddhudu, FJ Bryant
    Solid State Communications 72 (9), 923-925 , 1989
    1989
    Citations: 17

MOST CITED SCHOLAR PUBLICATIONS

  • Spectroscopic properties of Tb3+-doped fluoride glasses
    G Amaranath, S Buddhudu, FJ Bryant
    Journal of non-crystalline solids 122 (1), 66-73 , 1990
    1990
    Citations: 59
  • Spectroscopic properties of Pr3+-doped multicomponent fluoride glasses
    G Amaranath, S Buddhudu, FJ Bryant, L Xi, B Yu, S Huang
    Materials research bulletin 25 (10), 1317-1323 , 1990
    1990
    Citations: 31
  • Optical properties of rare-earth-doped HMF glasses
    G Amaranath, S Buddhudu
    Journal of non-crystalline solids 143, 252-256 , 1992
    1992
    Citations: 27
  • Spectroscopic properties of Nd3+-doped heavy metal fluoride glasses
    G Amaranath, S Buddhudu, FJ Bryant, L Xi, B Yu, S Huang
    Journal of luminescence 47 (5), 255-260 , 1991
    1991
    Citations: 18
  • Emission properties of Tb3+-doped alkali mixed fluoride glasses
    G Amaranath, S Buddhudu, FJ Bryant
    Solid State Communications 72 (9), 923-925 , 1989
    1989
    Citations: 17
  • Luminescence properties of Nd3+ in mixed alkali flouride glasses
    G Amaranath, S Buddhudu, FJ Bryant, L Xi, B Yu, S Huang
    Journal of luminescence 50 (1), 17-20 , 1991
    1991
    Citations: 16
  • Fluorescence spectral properties of Sm3+-and Dy3+-doped laser liquids
    NS Hussain, K Annapurna, DVV Rao, KR Reddy, G Amaranath, ...
    Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 53 (5 … , 1997
    1997
    Citations: 5
  • Photoluminescence spectra of Er 3+ -doped fluorophosphate glasses
    AVR Reddy, K Annapurna, G Amaranath, AS Jacob, AK Suresh, ...
    Ferroelectrics Letters Section 14 (5-6), 145-159 , 1992
    1992
    Citations: 4
  • Optical Properties of Ho(NO 3 ) 3 6H 2 O: Organic Acid Complexes
    S Buddhudu, VN Rangarajan, G Amaranath, R Harinath, AS Kumar
    Physics and Chemistry of Liquids 23 (2), 61-68 , 1991
    1991
    Citations: 2
  • Nonlinearity and elastic properties of Cr (3+): Al2O3 and Ti (3+): Al2O3 laser crystals
    G Amaranath, S Buddhudu, A Mandelis
    Solid state communications 91 (9), 761-763 , 1994
    1994
    Citations: 1
  • Optical Absorption And Luminescence Properties Of Certain Rare Earths Doped Heavy Metal Fluoride Glasses
    G Amaranath
    1991
  • AbuHadba, N. and CR Aita, Growth and near-ultraviolet optical absorption char-acteristics of sputter deposited nominal germania Aita, CR, see AbuHadba
    G Amaranath, S Buddhudu, FJ Bryant, MA Aysawy, A Szasz, L Kertesz, ...
    Journal of Non-Crystalline Solids 122, 319-321 , 1990
    1990