Bucharest University - Physics Department
Teaching Assistant Drd. Valentin Barna


Personal Data
  • First name: BARNA
    Surname: VALENTIN
  • Birth date: 30-06-1980.
    Adress: Magurele, P.O.Box Mg. 11, Romānia

Scientific Research Activity

Domains of Interest:

  • Photonic Bandgap Materials (Photonic Crystals & Chiral Liquid Crystals);
  • Lasing in Periodic, Quasiperiodic and Random Media;
  • Physical properties of confined Liquid Crystal materials in sculptured polymeric microcavities presenting different geometries;
  • Random Lasing and Weak Localization of Light in Nematic Liquid Crystals;
  • Physical study of new polymeric materials obtained via plasma polymerization technique;
  • Instabilities in thin polymer films - structure formation and pattern transfer;
  • Surfaces and Interactions in Nematic Liquid Crystals - Thin Plasma Polymeric Layers;
  • AFM nano-patterning of Polymeric Substrates.
List Of Scientific Publications

ISI Articles:

  1. "A model of melt-solid phase transition in liniar polymers" V. Barna, C.Miron, C.Berlic, E.S.Barna. Plastic Materials, 40, 4, p.168-172, (2003)
  2. "Fast electro-optic switching in nematic liqiud crystals" A.L.Ionescu, A.Ionescu, E.S.Barna, V. Barna, N. Scaramuzza, Applied Physics Letters Vol 84(1) pp. 40-42. January 5, (2004)
  3. "Molecular simulation of the free surface order in NLC samples" N. Scaramuzza, C.Berlic, V. Barna, E.S.Barna, G.Strangi, A.Ionescu, J.Phys.Chem.B, 108(10), 3207-3210, (2004)
  4. "Role of delocalized electrons in polyaniline - nematogen cyanobiphenyls interaction" A.L.Ionescu, A.Ionescu, E.S.Barna, V. Barna, N. Scaramuzza, J.Phys.Chem.B 108(26), 8894-8899, (2004)
  5. "Preliminary FTIR measurements of the anchoring properties of the Liquid Crystal (5CB) on Polyaniline substrate in Hybrid LC Cells using conventional infrared (IR) sources at DAFNE-L Laboratory" V. Barna, C.Miron, C.Berlic, E.S.Barna Plastic Materials, 41, 1, p15-21, (2004)
  6. "Color Tunable Distributed Feedback Organic Micro-Cavity Laser" G. Strangi, V. Barna, R. Caputo, A. de Luca, C. Versace, N. Scaramuzza, C. Umeton, R..Bartolino, G.Price Physical Review Letters 94, 063903, (2005)
  7. "Color-Tunable Organic Microcavity Laser Array Using Distributed Feedback" Strangi G. , Barna V. , Caputo R. , De Luca A. , Versace C. , Scaramuzza N. , Umeton C. P. , Bartolino R. , Price G. Virtual Journal of Nanoscale Science and Technology, Vol. 11, n.8, (2005)
  8. "Band-Edge and Defect Modes Lasing Due to Confinement of Helixed Liquid Crystals in Cylindrical Microcavities" Barna V. , Ferjani S. , Strangi G. , De Luca A. ,Versace C. , Scaramuzza N. Published as article in Appl. Phys. Lett. 87, 221108 (2005) Published as cover in Applied Physics Letters November 2005 Issue.
  9. "Distributed Feedback Micro-Laser Array: Helixed Liquid Crystals Embedded in Holographically Sculptured Polymeric Microcavities" Barna V., Caputo R., De Luca A., Scaramuzza N., Strangi G.,Versace C., Umeton C., Bartolino R., Price G. Optics Express, 14, 7, 2695-2705 (2006)
  10. "Random Lasing and Weak Localization of Light in Nematic Liquid Crystals" Strangi G., Barna V., Ferjani S. et al. To be published in Phys.Rev.Lett.

International Patents:

  1. "Transient interface charged layer effect (TICLE) on the relaxation of electro-optic switching in nematic liquid crystals to build electro-optical devices" A. Ionescu, A.L. Alexe-Ionescu, N. Scaramuzza, V. Barna, E.S. Barna, Italian Patent DF 03 A 0002376, 28-05-2003
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