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F Marin - One of the best experts on this subject based on the ideXlab platform.

  • bragg section effects on linewidth and Lineshape in 1 55 spl mu m dbr tunable laser diodes
    IEEE Photonics Technology Letters, 2004
    Co-Authors: P. Signoret, M. Myara, J.-p. Tourrenc, B. Orsal, M.-h. Monier, J. Jacquet, P. Leboudec, F Marin
    Abstract:

    We report linewidth and Lineshape measurements on 1.55-/spl mu/m distributed Bragg reflector tunable laser diodes using the heterodyne method. We measure Lorentzian linewidths ranging from 3.5 to 25 MHz without any passive section injection. Biasing the Bragg section enhances the residual linewidth up to 6.2 MHz, changes the linewidth-power product, and brings an additional Gaussian Lineshape. The feedback sensitivity of the overall setup is also demonstrated.

  • Bragg section effects on linewidth and Lineshape in 1.55-μm DBR tunable laser diodes
    IEEE Photonics Technology Letters, 2004
    Co-Authors: P. Signoret, M. Myara, J.-p. Tourrenc, B. Orsal, M.-h. Monier, J. Jacquet, P. Leboudec, F Marin
    Abstract:

    We report linewidth and Lineshape measurements on 1.55-μm distributed Bragg reflector tunable laser diodes using the heterodyne method. We measure Lorentzian linewidths ranging from 3.5 to 25 MHz without any passive section injection. Biasing the Bragg section enhances the residual linewidth up to 6.2 MHz, changes the linewidth-power product, and brings an additional Gaussian Lineshape. The feedback sensitivity of the overall setup is also demonstrated.

  • Lineshape of a vertical cavity surface emitting laser
    Optics Communications, 2002
    Co-Authors: Silvia Viciani, Mathias Gabrysch, F Marin, Fabrice Monti Di Sopra, M Moser, Karl Heinz Gulden
    Abstract:

    We report on the experimental study of the Lineshape of an air-post GaAs/AlGaAs Vertical-Cavity Surface-Emitting Laser (VCSEL). The signal is obtained by heterodyne with a narrow linewidth extended-cavity laser. This technique allows to fully take into account the entire spectrum of frequency fluctuations. In this way we can distinguish a Lorentzian and a Gaussian contributions to the Lineshape, obtaining a clear picture of the dependence of the emission spectrum on the pump current. The study also includes the effects on the laser Lineshape of the secondary transverse modes fluctuations.

Marcus A. Hemminga - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of 31P nuclear magnetic resonance Lineshapes and transversal relaxation of bacteriophage M13 and tobacco mosaic virus.
    Biophysical journal, 1993
    Co-Authors: Pieter C M M Magusin, Marcus A. Hemminga
    Abstract:

    The experimentally observed 31P Lineshapes and transversal relaxation of 15% (wt/wt) M13, 30% M13, and 30% tobacco mosaic virus (TMV) are compared with Lineshapes and relaxation curves that are simulated for various types of rotational diffusion using the models discussed previously (Magusin, P. C. M. M., and M. A. Hemminga. 1993. Biophys. J. 64:1851-1860). It is found that isotropic diffusion cannot explain the observed Lineshape effects. A rigid rod diffusion model is only successful in describing the experimental data obtained for 15% M13. For 30% M13 the experimental Lineshape and relaxation curve cannot be interpreted consistently and the TMV Lineshape cannot even be simulated alone, indicating that the rigid rod diffusion model does not generally apply. A combined diffusion model with fast isolated motions of the encapsulated nucleic acid dominating the Lineshape and a slow overall rotation of the virion as a whole, which mainly is reflected in the transversal relaxation, is able to provide a consistent picture for the 15 and 30% M13 samples, but not for TMV. Strongly improved Lineshape fits for TMV are obtained assuming that there are three binding sites with different mobilities. The presence of three binding sites is consistent with previous models of TMV. The best Lineshapes are simulated for a combination of one mobile and two static sites. Although less markedly, the assumption that two fractions of DNA with different mobilities exist within M13 also improves the simulated Lineshapes. The possible existence of two 31P fractions in M13 sheds new light on the nonintegral ratio 2.4:1 between the number of nucleotides and protein coat subunits in the phage: 83% of the viral DNA is less mobile, suggesting that the binding of the DNA molecule to the protein coat actually occurs at the integral ratio of two nucleotides per protein subunit.

  • Analysis of P-31 Nuclear Magnetic Resonance Lineshapes and Transversal Relaxation of Bacteriophage-M13 and Tobacco Mosaic Virus
    Biophys. J., 1993
    Co-Authors: Pieter C M M Magusin, Marcus A. Hemminga
    Abstract:

    The experimentally observed P-31 Lineshapes and transversal relaxation of 15% (wt/wt) M13, 30% M13, and 30% tobacco mosaic virus (TMV) are compared with Lineshapes and relaxation curves that are simulated for various types of rotational diffusion using the models discussed previously (Magusin, P. C. M. M., and M. A. Hemminga. 1993. Biophys. J. 64:1851-1860). It is found that isotropic diffusion cannot explain the observed Lineshape effects. A rigid rod diffusion model is only successful in describing the experimental data obtained for 15% M13. For 30% M13 the experimental Lineshape and relaxation curve cannot be interpreted consistently and the TMV Lineshape cannot even be simulated alone, indicating that the rigid rod diffusion model does not generally apply. A combined diffusion model with fast isolated motions of the encapsulated nucleic acid dominating the Lineshape and a slow overall rotation of the virion as a whole, which mainly is reflected in the transversal relaxation, is able to provide a consistent picture for the 15 and 30% M13 samples, but not for TMV. Strongly improved Lineshape fits for TMV are obtained assuming that there are three binding sites with different mobilities. The presence of three binding sites is consistent with previous models of TMV. The best Lineshapes are simulated for a combination of one mobile and two static sites. Although less markedly, the assumption that two fractions of DNA with different mobilities exist within M13 also improves the simulated Lineshapes. The possible existence of two P-31 fractions in M13 sheds new light on the nonintegral ratio 2.4:1 between the number of nucleotides and protein coat subunits in the phage: 83% of the viral DNA is less mobile, suggesting that the binding of the DNA molecule to the protein coat actually occurs at the integral ratio of two nucleotides per protein subunit.MA Hemminga/Agr Univ Wageningen/Dept Molec Phys/POB 8128/6700 Et Wageningen, Netherlands

P. Signoret - One of the best experts on this subject based on the ideXlab platform.

Pieter C M M Magusin - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of 31P nuclear magnetic resonance Lineshapes and transversal relaxation of bacteriophage M13 and tobacco mosaic virus.
    Biophysical journal, 1993
    Co-Authors: Pieter C M M Magusin, Marcus A. Hemminga
    Abstract:

    The experimentally observed 31P Lineshapes and transversal relaxation of 15% (wt/wt) M13, 30% M13, and 30% tobacco mosaic virus (TMV) are compared with Lineshapes and relaxation curves that are simulated for various types of rotational diffusion using the models discussed previously (Magusin, P. C. M. M., and M. A. Hemminga. 1993. Biophys. J. 64:1851-1860). It is found that isotropic diffusion cannot explain the observed Lineshape effects. A rigid rod diffusion model is only successful in describing the experimental data obtained for 15% M13. For 30% M13 the experimental Lineshape and relaxation curve cannot be interpreted consistently and the TMV Lineshape cannot even be simulated alone, indicating that the rigid rod diffusion model does not generally apply. A combined diffusion model with fast isolated motions of the encapsulated nucleic acid dominating the Lineshape and a slow overall rotation of the virion as a whole, which mainly is reflected in the transversal relaxation, is able to provide a consistent picture for the 15 and 30% M13 samples, but not for TMV. Strongly improved Lineshape fits for TMV are obtained assuming that there are three binding sites with different mobilities. The presence of three binding sites is consistent with previous models of TMV. The best Lineshapes are simulated for a combination of one mobile and two static sites. Although less markedly, the assumption that two fractions of DNA with different mobilities exist within M13 also improves the simulated Lineshapes. The possible existence of two 31P fractions in M13 sheds new light on the nonintegral ratio 2.4:1 between the number of nucleotides and protein coat subunits in the phage: 83% of the viral DNA is less mobile, suggesting that the binding of the DNA molecule to the protein coat actually occurs at the integral ratio of two nucleotides per protein subunit.

  • Analysis of P-31 Nuclear Magnetic Resonance Lineshapes and Transversal Relaxation of Bacteriophage-M13 and Tobacco Mosaic Virus
    Biophys. J., 1993
    Co-Authors: Pieter C M M Magusin, Marcus A. Hemminga
    Abstract:

    The experimentally observed P-31 Lineshapes and transversal relaxation of 15% (wt/wt) M13, 30% M13, and 30% tobacco mosaic virus (TMV) are compared with Lineshapes and relaxation curves that are simulated for various types of rotational diffusion using the models discussed previously (Magusin, P. C. M. M., and M. A. Hemminga. 1993. Biophys. J. 64:1851-1860). It is found that isotropic diffusion cannot explain the observed Lineshape effects. A rigid rod diffusion model is only successful in describing the experimental data obtained for 15% M13. For 30% M13 the experimental Lineshape and relaxation curve cannot be interpreted consistently and the TMV Lineshape cannot even be simulated alone, indicating that the rigid rod diffusion model does not generally apply. A combined diffusion model with fast isolated motions of the encapsulated nucleic acid dominating the Lineshape and a slow overall rotation of the virion as a whole, which mainly is reflected in the transversal relaxation, is able to provide a consistent picture for the 15 and 30% M13 samples, but not for TMV. Strongly improved Lineshape fits for TMV are obtained assuming that there are three binding sites with different mobilities. The presence of three binding sites is consistent with previous models of TMV. The best Lineshapes are simulated for a combination of one mobile and two static sites. Although less markedly, the assumption that two fractions of DNA with different mobilities exist within M13 also improves the simulated Lineshapes. The possible existence of two P-31 fractions in M13 sheds new light on the nonintegral ratio 2.4:1 between the number of nucleotides and protein coat subunits in the phage: 83% of the viral DNA is less mobile, suggesting that the binding of the DNA molecule to the protein coat actually occurs at the integral ratio of two nucleotides per protein subunit.MA Hemminga/Agr Univ Wageningen/Dept Molec Phys/POB 8128/6700 Et Wageningen, Netherlands

J.-p. Tourrenc - One of the best experts on this subject based on the ideXlab platform.