排序方式: 共有39条查询结果,搜索用时 31 毫秒
11.
Prislopski SY Naumenko EK Tiginyanu IM Ghimpu L Monaico E Sirbu L Gaponenko SV 《Optics letters》2011,36(16):3227-3229
Pronounced retroreflection behavior is reported for a fishnet nanoporous strongly absorbing semiconductor material. Retroreflection features a half-cone about 0.35 rad along with diffusive specular reflection for all angles of incidence. Retroreflection is apparent by the naked eye with daylight illumination and exhibits no selectivity with respect to wavelength and polarization of incident light featuring minor depolarization of retroreflected light. The reflectance in the backward direction measures 12% with respect to a white scattering etalon. The phenomenon can be classified neither as coherent backscattering nor as Anderson localization of light. The primary model includes light scattering from strongly absorptive and refractive superwavelength clusters existing within the porous fishnet structure. A reasonable qualitative explanation is based on the fact that strict retroreflection obeys shorter paths inside absorbing medium, whereas all alternative paths will lead to stronger absorption of light. 相似文献
12.
Eduard Monaico Petru Tighineanu Sergiu Langa Hans L. Hartnagel Ion Tiginyanu 《固体物理学:研究快报》2009,3(4):97-99
We show that anodic etching of n‐type ZnSe crystalline substrates leads to the formation of pores which, after nucleation at surface defects, prove to follow the current lines, exhibiting multiplication until the front of the porous network covers the whole available space. No growth of crystallographically oriented pores has been observed in ZnSe. The formation of multilayer porous structures is realized, including layers subjected to successive porosification at two different length scales. The electrochemical pulsed deposition of arrays of Pt nanotubes in the porous ZnSe matrix is demonstrated. The obtained results show that porous ZnSe structures are promising for use as conductive and optically transparent nanotemplates for nanofabrication, in particular for the important application of metal nanotubes. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
13.
14.
15.
16.
17.
18.
V. V. Zalamai V. V. Ursaki I. M. Tiginyanu A. Burlacu E. V. Rusu C. Klingshirn J. Fallert J. Sartor H. Kalt 《Applied physics. B, Lasers and optics》2010,99(1-2):215-222
High optical quality, well end leg faceted ZnO microtetrapods with leg length between 1 and 12 μm have been grown by carbothermal chemical vapor deposition. Lasing with mode quality factors of 2500–3000 is demonstrated. The origin of laser resonator cavity is discussed as a function of the tetrapod size. It is shown that in big tetrapods with legs of 12 μm in length the laser emission lines are well explained by longitudinal Fabry–Pérot modes generated in cavities formed by individual tetrapod legs. The dispersion of the ZnO refractive index is experimentally determined from the position of lasing modes in the temperature interval from 10 to 300 K. It is shown that the lasing mode structure is seriously affected by the decrease of the tetrapod size. For a small tetrapod with a leg length of 1 μm, the lasing modes cannot be explained anymore by the formation of longitudinal Fabry–Pérot modes in separate tetrapod legs, and the generation of guided modes by multiple total internal reflections in single tetrapod legs or in pairs of legs should be taken into account. The correlations between the lasing threshold and the tetrapod size are discussed. 相似文献
19.
20.
O. Yilmazoglu D. Pavlidis Yu. M. Litvin S. Hubbard I. M. Tiginyanu K. Mutamba H. L. Hartnagel V. G. Litovchenko A. Evtukh 《Applied Surface Science》2003,220(1-4):46-50
Whisker structures and quantum dots fabricated by photoelectrochemical (PEC) etching of undoped and doped metalorganic chemical vapor deposition (MOCVD)-grown GaN (2×1017 or 3×1018 cm−3) are investigated in relation with their field-emission characteristics. Different surface morphologies, corresponding to different etching time and photocurrent, results in different field-emission characteristics with low turn-on voltage down to 4 V/μm and the appearance of quantum-size effect in the I–V curves. 相似文献