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411.
Low-noise, tunable wavelength-conversion through nondegenerate four-wave mixing Bragg scattering in SiN(x) waveguides is experimentally demonstrated. Finite element method simulations of waveguide dispersion are used with the split-step Fourier method to predict device performance. Two 1550 nm wavelength band pulsed pumps are used to achieve tunable conversion of a 980 nm signal over a range of 5 nm with a peak conversion efficiency of ≈5%. The demonstrated Bragg scattering process is suitable for frequency conversion of quantum states of light. 相似文献
412.
L Nugent-Glandorf T Neely F Adler AJ Fleisher KC Cossel B Bjork T Dinneen J Ye SA Diddams 《Optics letters》2012,37(15):3285-3287
We present and characterize a two-dimensional (2D) imaging spectrometer based on a virtually imaged phased array (VIPA) disperser for rapid, high-resolution molecular detection using mid-infrared (MIR) frequency combs at 3.1 and 3.8?μm. We demonstrate detection of CH4 at 3.1?μm with >3750 resolution elements spanning >80 nm with ~600 MHz resolution in a <10 μs acquisition time. In addition to broadband detection, we also demonstrate rapid, time-resolved single-image detection by capturing dynamic concentration changes of CH4 at a rate of ~375 frames per second. Changes in absorption above the noise floor of 5×10-4 are readily detected on the millisecond time scale, leading to important future applications such as real-time monitoring of trace gas concentrations and detection of reactive intermediates. 相似文献
413.
Dr. Bethany R. Hood Dr. Yovan de Coene Afonso V. Torre Do Vale Froes Dr. Claire F. Jones Dr. Pierre Beaujean Dr. Vincent Liégeois Dr. Fraser MacMillan Prof. Benoît Champagne Prof. Koen Clays Dr. John Fielden 《Angewandte Chemie (International ed. in English)》2023,62(5):e202215537
Electrochemically switched 2nd order non-linear optical responses have been demonstrated for the first time in polyoxometalates (POMs), with an arylimido-derivative showing a leading combination of high on/off contrast (94 %), high visible transparency, and cyclability. Spectro-electrochemical and TD-DFT studies indicate that the switch-off results from weakened charge transfer (CT) character of the electronic transitions in the reduced state. This represents the first study of an imido-POM reduced state, and demonstrates the potential of POM hybrids as electrochemically activated molecular switches. 相似文献
414.
A. Kakanakova-Georgieva E. P. Trifonova R. Yakimova M. F. MacMillan E. Janzen 《Crystal Research and Technology》1999,34(8):943-947
Knoop microhardness of 6H-SiC layers grown by sublimation epitaxy was investigated. The microhardness-load curves for all of the samples were measured and then used to extract the load-independent microhardness values. The relationships of these values to the growth time and growth rate were studied. The microhardness-depth profiles indicated that the layer/substrate interface region had a microhardness value that differed significantly from that of both the epi-layer and the substrate. 相似文献
415.
Eric Bosch Bryce S. Moreno Nathan P. Bowling 《Acta Crystallographica. Section C, Structural Chemistry》2023,79(4):149-157
The present study evaluates the potential combination of charge-transfer electron-donor–acceptor π–π complexation and C—H hydrogen bonding to form colored cocrystals. The crystal structures of the red 1:1 cocrystals formed from the isomeric pyridines 4- and 3-{2-[4-(dimethylamino)phenyl]ethynyl}pyridine with 1-[2-(3,5-dinitrophenyl)ethynyl]-2,3,5,6-tetrafluorobenzene, both C14H4F4N2O4·C15H14N2, are reported. Intermolecular interaction energy calculations confirm that π-stacking interactions dominate the intermolecular interactions within each crystal structure. The close contacts revealed by Hirshfeld surface calculations are predominantly C—H interactions with N, O, and F atoms. 相似文献