J. H. Rohling

Publications (25)33.02 Total impact

• Article: A 3-dimensional time-resolved photothermal deflection mirage method

  N.G.C. Astrath, L.C. Malacarne, G.V.B. Lukasievicz, H.S. Bernabe, J.H. Rohling, M.L. Baesso, J. Shen, S.E. Bialkowski
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  ABSTRACT: Export Date: 18 July 2012, Source: Scopus, Art. No.: 091908, CODEN: APPLA, doi: 10.1063/1.3691253, Language of Original Document: English, Correspondence Address: Astrath, N.G.C.; Departamento de Física, Universidade Estadual de Maringá, Maringá, PR 87020-900, Brazil; email: astrathngc@pq.cnpq.br, References: Vargas, H., Miranda, L.C.M., (1988) Phys. Rep., 161, p. 43. , 10.1016/0370-1573(88)90100-7;
  Applied Physics Letters 01/2012; 100(9). · 3.84 Impact Factor
• Article: Temperature dependence of the thermophysical properties of Neodymium doped borate glasses

  N.G.C. Astrath, L.C. Malacarne, J.H. Rohling, A.N. Medina, M.L. Baesso, A. Steimacher, C. Jacinto, B. Karthikeyan
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  ABSTRACT: Export Date: 18 July 2012, Source: Scopus, CODEN: OMATE, doi: 10.1016/j.optmat.2011.02.050, Language of Original Document: English, Correspondence Address: Astrath, N.G.C.; Departamento de Física, Universidade Estadual de Maringá, Av. Colombo 5790, 87020-900 Maringá, PR, Brazil; email: astrathngc@pq.cnpq.br, References: Sugimoto, N., Kanbara, H., Fujwara, S., Tanaka, K., (1996) Opt. Lett., 21, p. 1637;
  Optical Materials. 01/2011; 33(11):1563-1568.
• Article: Study on the observation of Eu2+ and Eu3+ valence states in low silica calcium aluminosilicate glasses.

  J A Sampaio, M C Filadelpho, A A Andrade, J H Rohling, A N Medina, A C Bento, L M da Silva, F C G Gandra, L A O Nunes, M L Baesso
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  ABSTRACT: The optical, magnetic and structural properties of Eu doped low silica calcium aluminosilicate glasses were investigated. The optical absorption coefficient presented two bands at 39,246 and 29,416 cm(-1), which were assigned respectively to the [Formula in text], and [Formula in text] transitions of Eu(2+). The fluorescence measured at 300 K on a sample doped with 0.5 wt% of Eu(2)O(3) exhibited a broad band centered at 17,350 cm(-1), which is attributed to the [Formula in text] transition of Eu(2+), whereas the additional peaks are due to the [Formula in text] transitions of Eu(3+). From magnetization and XANES data it was possible to evaluate the fractions of Eu(2+) and Eu(3+) for the sample doped with 0.5 and 5.0 wt% of Eu(2)O(3), the values of which were approximately 30 and 70%, respectively.
  Journal of Physics Condensed Matter 02/2010; 22(5):055601. · 2.55 Impact Factor
• Article: Investigation of doped calcium aluminosilicate glass: A coupling between thermal-expansion and thermal-diffusion models for assessment of nonradiative relaxation time and characteristic diffusion time

  N. E. Souza Filho, A. C. Nogueira, J. H. Rohling, M. L. Baesso, A. N. Medina, A. P. L. Siqueira, J. A. Sampaio, H. Vargas, A. C. Bento
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  ABSTRACT: This paper discusses the use of photoacoustic models to obtain the nonradiative relaxation time (τ) and characteristic diffusion time (τ_β) for a sample showing visible absorption bands from fluorescent ion-doped low-silica calcium aluminosilicate glass. Two models allowing phase shift analyses, the thermal-expansion and thermal-diffusion models, are briefly reviewed. These models have limitations when the photoacoustic signal depends on both factors, in a coupling mechanism. An alternative model is proposed to take both thermal expansion and thermal diffusion into account with a single temperature solution for the heat-coupled differential equation. This model is simulated for absorbing samples near the thermally thick region. The model is applied to Eu–V codoped glass showing intermediate signal dependence from ω^-1.0 to ω^-3/2 . The nonradiative time and characteristic diffusion time are derived with 33≪τ( ms )≪39 , and τ_β( ms )∼70 ms for the Eu-ion and 340≪τ_β( ms )≪710 for the V-ion. Four absorption bands were analyzed (280, 350, 420, and 600 nm), which showed a signal dependence from ω^-1.1 to ω^-1.52 . Absorption coefficients were derived from τ_β in the range of 15≪β( cm ^-1)≪51 , which agreed fairly well with spectrophotometer data for the same ions.
  Journal of Applied Physics 12/2009; · 2.17 Impact Factor
• Article: A step forward toward smart white lighting: Combination of glass phosphor and light emitting diodes

  L. H. C. Andrade, S. M. Lima, A. Novatski, A. Steimacher, J. H. Rohling, A. N. Medina, A. C. Bento, M. L. Baesso, Y. Guyot, G. Boulon
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  ABSTRACT: We present our recent achievements of a glass able to produce smart white light combining a glass phosphor with light emitting diodes (LEDs). The combined emissions of Ce3+-doped calcium aluminosilicate glass and the 405 nm LED using the Commission Internationale de l’Éclairage 1931 chromatic diagram showed that this system presents an emission close to the ideal white light and allows tunability. In addition, the glass blue emission overlaps with the spectral range of the retinal photoreceptors involved in circadian responses. This glass combined with UV LED emission is suitable for circadian lights and therefore may contribute to improve environmental lighting and human well being.
  Applied Physics Letters 08/2009; 95(8):081104-081104-3. · 3.84 Impact Factor
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  Available from: Nelson G. C. Astrath

  Article: Thermal lens and interferometric method for glass transition and thermo physical properties measurements in Nd2O3 doped sodium zincborate glass.

  N G C Astrath, A Steimacher, J H Rohling, A N Medina, A C Bento, M L Baesso, C Jacinto, T Catunda, S M Lima, B Karthikeyan
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  ABSTRACT: In this work the time resolved thermal lens method is combined with interferometric technique, the thermal relaxation calorimetry, photoluminescence and lifetime measurements to determine the thermo physical properties of Nd(2)O(3) doped sodium zincborate glass as a function of temperature up to the glass transition region. Thermal diffusivity, thermal conductivity, fluorescence quantum efficiency, linear thermal expansion coefficient and thermal coefficient of electronic polarizability were determined. In conclusion, the results showed the ability of thermal lens and interferometric methods to perform measurements very close to the phase transition region. These techniques provide absolute values for the measured physical quantities and are advantageous when low scan rates are required.
  Optics Express 01/2009; 16(26):21248-55. · 3.59 Impact Factor
• Article: Study of anisotropy in the temperature coefficient of the optical path length of axial single crystals using an interferometric technique

  O A Sakai, A Steimacher, J H Rohling, A C Bento, M L Baesso, A N Medina
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  ABSTRACT: The interferometric technique was used to study the temperature coefficient of the optical path length (dS/dT) of different crystallographic axes of single crystals SiO2 and LiSrAlF6 within the temperature range 298–453 K. Using a randomly polarized laser beam incident in a single crystal, in which the c-axis is the surface, a 'modulation effect' in the interferogram pattern was observed. The dS/dT values for different crystallographic axes of the single crystals were determined by using the interferogram and a two beam reflection theory that takes into account the superposition of the beams. The results were confirmed using a polarized laser and show a good agreement with the literature. The great advantage of this simple and low cost interferometric technique was verified in crystals with anisotropy. Estimated values of dS/dT relative to different optical axes were determined with a single measurement.
  Journal of Physics D Applied Physics 11/2008; 41(24):245406. · 2.54 Impact Factor
• Article: Low temperature specific heat of doped and undoped glasses

  N.G.C. Astrath, A. Steimacher, A.N. Medina, J.H. Rohling, J.R.D. Pereira, A.C. Bento, M.L. Baesso, L.M. da Silva, F.G. Gandra
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  ABSTRACT: Cited By (since 1996): 2, Export Date: 18 July 2012, Source: Scopus, CODEN: JNCSB, doi: 10.1016/j.jnoncrysol.2006.03.088, Language of Original Document: English, Correspondence Address: Astrath, N.G.C.; Departamento de Física, Universidade Estadual de Maringá, Av. Colombo 5790, 87020-900 Maringá, PR, Brazil; email: astrath@dfi.uem.br, References: Zeller, R.C., Pohl, R.O., (1971) Phys. Rev. B, 4, p. 2029;
  Journal of Non-Crystalline Solids 01/2006; 352(32-35):3572-3576. · 1.54 Impact Factor
• Conference Proceeding: Fluorescence quantum efficiency in Nd2O3-doped aluminosilicate glasses by multiwavelength thermal lens method

  N.G.C. Astrath, J.H. Rohling, A.C. Bento, M.L. Baesso, C. Jacinto, S.M. Lima, L.A.O. Nunes, T. Catunda
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  ABSTRACT: Conference code: 66918, Cited By (since 1996): 6, Export Date: 18 July 2012, Source: Scopus, CODEN: JPICE, doi: 10.1051/jp4:2005125043, Language of Original Document: English, Correspondence Address: Astrath, N.G.C.; Dep. de Física, Universidade Estadual de Maringá, CEP 87020-900, Maringá, PR, Brazil, References: Lima, S.M., Andrade, A.A., Catunda, T., Lebullenger, R., Hernandes, A.C., Baesso, M.L., (2001) Appl. Phys. Letters, 78, p. 3220;, Sponsors: State University of the North of Rio de Janeiro, Brazil; State University of Campinas; National Institute for Space Research; State of Rio de Janeiro Research Foundation; State of Sao Paulo Research Foundation
  Journal De Physique. IV : JP, Rio de Janeiro; 01/2005
• Article: Time-resolved thermal lens measurements of the thermo-optical properties of glasses at low temperature down to 20 K

  N.G.C. Astrath, J.H. Rohling, A.N. Medina, A.C. Bento, M.L. Baesso, C. Jacinto, T. Catunda, S.M. Lima, F.G. Gandra, M.J.V. Bell, V. Anjos
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  ABSTRACT: Cited By (since 1996): 27, Export Date: 18 July 2012, Source: Scopus, Art. No.: 214202, CODEN: PRBMD, doi: 10.1103/PhysRevB.71.214202, Language of Original Document: English, Correspondence Address: Astrath, N.G.C.; Departamento de Física, Universidade Estadual de Maringá, 87020-900, Maringá - PR, Brazil, References: Touloukian, L.R., Powel, R.W., Ho, Y.C., Nicalasu, M.C., (1973) Thermal Diffusivity, , Plenum, New York;
  Physical Review B - Condensed Matter and Materials Physics. 01/2005; 71(21).
• Source

  Available from: Mauro Luciano Baesso

  Article: Time-resolved thermal lens determination of the thermo-optical coefficients in Nd-doped yttrium aluminum garnet as a function of temperature

  A. R. Nunes, J. H. Rohling, A. N. Medina, J. R. D. Pereira, A. C. Bento, M. L. Baesso, L. A. O. Nunes, T. Catunda
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  ABSTRACT: In this work, time-resolved thermal lens measurements are carried out in Nd-doped yttrium aluminum garnet laser crystal as a function of temperature. The temperature coefficient of the optical path length, the thermal diffusivity, and the thermal conductivity were determined in the temperature range between 22 °C and 180 °C. In addition, the specific heat was measured by the thermal relaxation method in the same temperature range. The results showed that the thermal conductivity and the temperature coefficient of the optical path length are responsible for the strong increase of the thermal lens amplitude when the sample temperature was increased. These results suggest that the time resolved procedure is useful in the study of laser materials and may be an important tool for laser designers.
  Applied Physics Letters 06/2004; 84(25):5183-5185. · 3.84 Impact Factor
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  Available from: Mauro Luciano Baesso

  Article: High fluorescence quantum efficiency of 1.8 μm emission in Tm-doped low silica calcium aluminate glass determined by thermal lens spectrometry

  S. L. Oliveira, S. M. Lima, T. Catunda, L. A. O. Nunes, J. H. Rohling, A. C. Bento, M. L. Baesso
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  ABSTRACT: In this work, thermal lens spectrometry is performed to determine the fluorescence quantum efficiency (η) of the 3F4 level (1.8 μm emission) of 4 and 5 wt % Tm-doped water free low silica calcium aluminate glass. The η value obtained for both high Tm contents was approximately 30%, which is in agreement with the Judd–Ofelt calculation. It is also verified that heat generation under 0.79 μm pumping, which presents a high quantum defect, is minimized by a cross-relaxation mechanism. The high η values, and the excellent chemical and thermomechanical properties indicate this system is a potential host material for diode-pumped laser sources operating in the midinfrared spectral range. © 2004 American Institute of Physics.
  Applied Physics Letters 01/2004; 84(3):359-361. · 3.84 Impact Factor
• Article: Laser emission at 1077 nm in Nd3+-doped calcium aluminosilicate glass

  D.F. de Sousa, L.A.O. Nunes, J.H. Rohling, M.L. Baesso
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  ABSTRACT: Laser emission at 1077nm (4F3/24I11/2) was demonstrated in Nd3+-doped low silica content calcium aluminosilicate (LSCA) glass under 810-nm pumping by a Ti:sapphire laser. The slope efficiency of the laser emission was found to be 34% with a 20-mW threshold power. The excited-state absorption (ESA) and stimulated emission were measured between 850 and 1520nm. The results showed two ESA bands from 931 to 1070nm (4F3/22D3/2,2G9/2,4G11/2,2K15/2) and from 1160 to 1414nm (4F3/2,4G9/24G7/2,2K13/2). The stimulated emission for the laser transition was found to be 45-nm broad with a peak value of 1.810-20cm2. Thermal and mechanical properties of the LSCA glass were compared to the ED-2 and LHG-8 glasses. While the mechanical properties of the LSCA glass are superior to those of the commercial glasses, its temperature coefficient of optical path length is the highest among the three hosts.
  Applied Physics B 01/2003; 77(1):59-63. · 2.19 Impact Factor
• Article: Thermal lens scanning of the glass transition in polymers

  J. H. Rohling, A. M. F. Caldeira, J.R.D. Pereira, A N Medina, A. C. Bento, M L Baesso, L. C. M. Miranda, A F Rubira
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  ABSTRACT: In this article we discuss the use of the thermal lens technique for investigating the thermal properties of polymers as a function of temperature. It is also discussed how the experimentally determined thermal lens parameters can be used to locate the glass transition in polymers. The methodology is tested using a solution casted films of poly(vinyl chloride) as a testing sample. A comparison with conventional differential scanning calorimetry data is made. It is proposed that the current transient thermal lens methodology, with minor changes in its experimental configuration, could be adapted to develop a new methodology called differential thermal lens scanning especially designed for the investigation of the phase transitions in polymers. It is shown that this new methodology could be equally used for the measurement of the thermal expansion coefficient, above and below the glass transition. Pages: 2220-2226
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  Available from: Mauro Luciano Baesso

  Article: Thermal lens versus DSC measurements for glass transition analysis of polymer

  J. H. Rohling, A N Medina, J.R.D. Pereira, A F Rubira, A. C. Bento, L. C. M. Miranda, M L Baesso
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  ABSTRACT: In this work thermal lens spectrometry is applied to investigate the thermo-optical properties of polymers as a function of the temperature. The method is applied in poly(vinyl chloride) as a testing sample. It is proposed that thermal lens spectrometry with minor change in its experimental configuration, could be adapted to develop a new tool, called differential thermal lens scanning, especially designed for the investigation of phase transition in polymers. Pages: S103-S105
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  Available from: Mauro Luciano Baesso

  Article: Temperature dependence of thermo-optical properties of optical glasses determined by Thermal Lens Spectrometry

  M L Baesso, E. Pelisson, J. H. Rohling, A N Medina, A. C. Bento, L. C. M. Miranda, S M Lima, J. A. Sampaio, T. Catunda
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  ABSTRACT: In this work we report on the use of thermal lens spectrometry to determine the temperature dependence of the thermo-optical properties, namely, thermal conductivity, thermal diffusivity, temperature coefficient of optical path length change and fluorescence quantum efficiency of ZBLAN and Nd2O3-doped low silica calcium aluminosilicate glasses. The results indicates that this technique can be used for the complete characterization of the thermo-optical properties of optical glasses as a function of temperature. Pages: S106-S109
• Article: Differential thermal lens temperature scanning approach to glass transition analysis in polymers: application to polycarbonate

  J. H. Rohling, A N Medina, A. C. Bento, J.R.D. Pereira, A F Rubira, M L Baesso, L. C. M. Miranda
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  ABSTRACT: In this paper, mode mismatched thermal lens spectrometry is applied to determine the thermal and optical properties of polycarbonate as a function of temperature. The focus of the experiments was in the temperature range between 120 °C and 170 °C, where the sample glass transitions occurs. In order to validate and evaluate the sensitivity of the proposed method we have also carried out conventional differential scanning calorimetry measurements. The results showed that the temperature dependence of the signal amplitude of the thermal lens provided a better definition in locating the glass transition compared to the differential scanning calorimetry data. In addition, a sharp decrease in the thermal diffusivity values at the beginning of the sample glass transition was observed. According to the Debye model, this change was attributed to the variation of the sample elastic constant throughout the glass transition. Finally, we propose this procedure, called the differential thermal lens temperature scanning approach, as a new method for the investigation of phase transitions in transparent polymers. Pages: 407-412
• Article: Thermo-optical properties of iron-doped low silica calcium aluminosilicate glasses determined by photothermal methods

  R.K. Miura, P T Udo, J. H. Rohling, E.A. Falcão, A N Medina, J.R.D. Pereira, A. C. Bento, M L Baesso, S L Oliveira, L.A.O. Nunes
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  ABSTRACT: The aim of this work is to investigate Fe$^{3+}$ and Fe$^{2+}$ influence on the thermo-optical properties of low silica calcium aluminosilicate glass. Conventional optical absorption spectroscopy, thermal relaxation calorimetry and thermal lens spectrometry were applied to analyze the samples. The results provided the specific heat, the thermal diffusivity and the optical absorption coefficient as a function of the ions concentration. A significant variation in these parameters was observed, revealing the influence of the iron ions on the glass structure.
  http://dx.doi.org/10.1051/jp4:2005125046.
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  Available from: Mauro Luciano Baesso

  Article: Influence of probe beam multi-reflection on thermal lens measurements: Application to Nd:YAG rods

  A.R. Nunes, J. H. Rohling, A N Medina, J.R.D. Pereira, A. C. Bento, M L Baesso, L.A.O. Nunes, T. Catunda
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  ABSTRACT: In this work time resolved thermal lens measurements were carried out in Nd-doped yttrium aluminum garnet laser crystal. We observed that due to the probe beam multi-reflection the thermal lens signal was influenced by the moving fringes that occurred in front of the detector. By using a heat sink device, this effect was minimized permitting the determination of the temperature coefficient of optical path length, the thermal diffusivity and the thermal conductivity of the sample. As a complementary technique, the thermal relaxation method was used to measure the sample specific heat.
  http://dx.doi.org/10.1051/jp4:2005125044.
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  Available from: Mauro Luciano Baesso

  Article: Thermal lens temperature scanning for quantitative measurements in transparent materials

  J H Rohling, J R D Pereira, A N Medina, A C Bento, M L Baesso, J A Sampaio, S M Lima, T Catunda, L C M Miranda
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  ABSTRACT: In this work the ability of thermal lens spectrometry for different temperature studies in transparent materials is discussed. The method was applied in polymers and optical glasses to measure the thermo-optical properties as a function of the temperature. The focus of the discussion will be on the temperature range where the glass transition occurs. The perspectives of future studies in this area will be discussed. © 2003 American Institute of Physics.