共查询到20条相似文献,搜索用时 415 毫秒
1.
Xinyuan Qi Ivan L. Garanovich Zhiyong Xu Andrey A. Sukhorukov Wieslaw Krolikowski Arnan Mitchell Guoquan Zhang Dragomir N. Neshev Yuri S. Kivshar 《Photonics and Nanostructures》2010,8(2):62-66
We study both theoretically and experimentally the nonlinear surface waves at the edge of curved waveguide arrays with a surface defect. We show that the nonlinear coupling between different linear modes supported by the array can lead to beam switching to different output waveguides with increasing of the nonlinearity strength. Our experimental observations are in good agreement with the numerical modelling. 相似文献
2.
Light propagation in uniform arrays of photonic crystal waveguides is studied. We demonstrate that, in stark contrast to the case of conventional waveguide arrays, diffraction can be tailored both in magnitude and sign by varying only the spacing between adjacent waveguides. Diffraction management in ultracompact arrays of straight photonic crystal waveguides is demonstrated by solving Maxwell's equations through the time-domain finite-element method. 相似文献
3.
Observation of switching phenomena in a nonether polyphenylquinoxaline planar waveguide with two-wavelength nonlinear prism coupling 总被引:1,自引:0,他引:1
We present research on nonether polyphenylquinoxaline film waveguides, and a scheme for an all-optical switching operation of waveguides is suggested. We use the m-line spectroscopy technique to characterize the guiding modes in the waveguide, and the switching phenomenon is observed with two-wavelength nonlinear prism coupling. The measured response time of the switching signal is less than 10(-9) s. 相似文献
4.
All-optical waveguide switching 总被引:2,自引:0,他引:2
We present a tutorial review of all-optical switching in fibre and integrated optics waveguides. These switching devices require non-linear refractive index changes in single or coupled waveguides, and involve either the low-power guided modes of the structure or soliton-type waves guided, emitted or captured by waveguides. We discuss the physical principles involved in these all-optical switching schemes, material requirements, recent experiments and limitations. A representative rather than comprehensive list of references is provided.An invited paper 相似文献
5.
We study resonant light scattering in arrays of channel optical waveguides in which tunable quadratic non-linearity is introduced as nonlinear defects by periodic poling of single (or several) waveguides in the array. We describe novel features of wave scattering that can be observed in this structure and show that it is a good candidate for observation of Fano resonance in nonlinear optics. 相似文献
6.
7.
U. Röpke H. Bartelt S. Unger K. Schuster J. Kobelke 《Applied physics. B, Lasers and optics》2011,104(3):481-486
Optical waveguide arrays consisting of a two-dimensional arrangement of weakly coupled waveguides represent the basis of the
new research field of discrete optics. For studying the nonlinear pulse dynamics, fiber waveguide arrays offer specific advantages
such as a high optical damage threshold and an accessible range of anomalous dispersion. Coherent coupling of such waveguides
for reasonable propagation lengths requires, however, a high structural quality of the waveguides and their superstructure,
which is beyond conventional fiber technology. Design, fabrication and characterization of such a fiber waveguide array are
described. The linear propagation properties in such a system are modeled and compared with experimental measurements. The
high structural homogeneity and good optical quality of the arrays as well as the limits of the nearest-neighbor approximation
are demonstrated. 相似文献
8.
A. Fratalocchi K. A. Rutkowska M. A. Karpierz G. Assanto 《Opto-Electronics Review》2007,15(4):210-214
We investigate all-optical Zener tunnelling in electro-optically tunable arrays of identical channel waveguides in undoped
nematic liquid crystals. By all-optically inducing a refractive acceleration, we demonstrate a novel technique for band-to-band
tunnelling, as well as a novel approach to light controlled steering and readdressing. 相似文献
9.
We study light propagation in nanoscale periodic structures composed of dielectric and metal in the visible range. We demonstrate that diffraction curves of nonuniform waveguide arrays can be tailored by varying the geometric and dielectric features of the waveguides. The results obtained from a proper formulation of coupled mode theory for nonuniform arrays are validated through numerical solution of Maxwell equations in frequency domain. 相似文献
10.
Formulas for calculating the spectral characteristics of waveguide arrays, which are incorporated into waveguide spectrum analyzers based on planar waveguides, channel waveguides, and fiber optical waveguides, are derived taking into account the contribution of both the waveguide dispersion and the material dispersion to the dispersion factor. These formulas are used to study the dependence of the dispersion factor on the waveguide-system parameters for specific models of waveguide arrays. It is shown that consideration of contributions of the waveguide dispersion and material dispersion can affect profoundly the spectral characteristics of waveguide arrays. 相似文献
11.
Chalcogenide glasses are promising candidates for all-optical switching and various nonlinear applications. However, we show that As2S3 thin films are photosensitive at wavelengths in the 1.5-microm telecommunication window. This sensitivity is evidenced by the formation of self-written waveguides in slabs, where channels as narrow as 1 microm are created. We also show the detrimental effects of such photosensitivity in ridge waveguides. This photosensitivity seems to occur only in thin-film form and not in bulk samples or fibers. 相似文献
12.
We demonstrate that light propagation in waveguide arrays that include PT-symmetric structures can exhibit strongly nonlocal sensitivity to topology of the array at fixed other parameters. We consider an array composed of lossless waveguides, that includes a pair of PT-symmetric waveguides with balanced gain and loss, and reveal that PT-symmetry breaking thresholds are different for planar and circular array configurations. These results demonstrate that PT-symmetric structures can offer new regimes for optical beam shaping compared to conservative structures. 相似文献
13.
Morandotti R Eisenberg HS Mandelik D Silberberg Y Modotto D Sorel M Stanley CR Aitchison JS 《Optics letters》2003,28(10):834-836
We investigated the interaction of discrete solitons with defect states fabricated in arrays of coupled waveguides. We achieved attractive and repulsive defects by decreasing and increasing, respectively, the spacing of one pair of waveguides in an otherwise uniform array. Linear and nonlinear propagation in the same samples show distinctly different properties. The role of the Peierls-Nabarro potential in the interaction of the soliton with the defect is discussed. 相似文献
14.
K. S. Buritskii E. M. Dianov V. A. Maslov V. A. Chernykh E. A. Scherbakov 《Applied physics. B, Lasers and optics》1992,54(2):167-169
We propose the use of KTP-based waveguides for all-optical switching. The passing of subnanosecond light pulses through the Rb:KTP nonlinear directional coupler is investigated. The nonlinear switching of 40% of light power from the one channel to another is observed at 5 kW input power. 相似文献
15.
A. Szameit H. Hartung F. Dreisow S. Nolte A. Tünnermann 《Applied physics. B, Lasers and optics》2007,87(1):17-20
We introduce a new technique to excite multiple waveguides in fs laser written waveguide arrays. Using a microstructured grating,
we were able to couple almost all of the power of the laser beam into multiple waveguides in one- and two-dimensional lattices.
Tilting the sample a defined phase shift between adjacent waveguides can be obtained, which allows anomalous diffraction and
refraction to be studied.
PACS 42.79.-e; 42.79.Gn; 42.82.Et; 42.25.Kb 相似文献
16.
By using the diffraction properties of waveguide arrays, we propose a scheme to produce structures with designed diffraction. We fabricated arrays with reduced, canceled, and even reversed diffraction. Results of experiments with such waveguides are presented and compared with the predictions made by coupled-mode theory. 相似文献
17.
We report the nonreciprocal behavior of an optical coupler consisting of two straight waveguides forming a small angle. An optical diode action is theoretically demonstrated when light is launched along opposite directions. The switching power is lower than the case of parallel waveguides with a constant coupling coefficient. 相似文献
18.
Szameit A Kartashov YV Dreisow F Heinrich M Pertsch T Nolte S Tünnermann A Vysloukh VA Torner L 《Optics letters》2008,33(10):1132-1134
We report the observation of surface solitons in chirped semi-infinite waveguide arrays whose waveguides exhibit exponentially decreasing refractive indices. We show that the power threshold for surface wave formation decreases with an increase of the array chirp and that for sufficiently large chirp values linear surface modes are supported. 相似文献
19.
F. P. Payne 《Optical and Quantum Electronics》2006,38(1-3):237-248
The purpose of this paper is to present an accurate analytical solution for the coupling between the array waveguides in arrayed waveguide grating (AWG) devices and star couplers. The results of this analysis will be useful for developing numerical models of AWGs and star couplers, as well as other optical waveguide components containing arrays of coupled waveguides. 相似文献
20.
We present the optical analysis of spatial single-mode monolithic quantum cascade laser arrays in the mid-IR. Subwavelength parallel microstripe waveguides are buried into InP:Fe and phase locked by evanescent coupling. Lasing at room temperature is obtained at λ=8.4 μm. We describe the near- and far-field of stripe arrays comprising up to 32 emitters. One hundred percent coherent emission is shown experimentally and well accounted for by a standard optical simulation. 相似文献