排序方式: 共有52条查询结果,搜索用时 0 毫秒
51.
We design novel photonic crystal heterostructure, substituting the air in the holes with materials of refractive index higher than n = 1. This can be achieved by infiltrating the photonic crystal (PC) with polymer. We theoretically investigate the L2 cavity with two missing holes in the center, where the six holes surrounding the cavity are locally filled with polymer. We show that cavity modes can be differently tuned depending on the size and the position of the first hole adjacent to the cavity. A photonic microcavity with a high Q factor of 5.5 × 106 and a modal volume V of 0.1919 is demonstrated. We demonstrate that the calculated Q factor for the designed cavity increases by a factor of 22 relative to that for a cavity without displaced and reduced air holes, while the modal volume remains almost constant. 相似文献
52.
Dr. Khouloud Hchicha Dr. Noureddine Mhadhbi Dr. Ahlem Guesmi Dr. Taoufik Soltani Dr. Naoufel Ben Hamadi Prof. Houcine Naïli 《欧洲无机化学杂志》2023,26(13):e202200696
S-substituted La2Mo2O9 were synthesized by a solid-state procedure employing ammonium sulfate (NH4)2SO4 as a sulfur source. The synthesized powders were examined using X-ray diffraction (XRD), thermogravimetric analysis (TGA), infrared, and Raman spectroscopies. The results divulged that the stabilization of the β-La2Mo2O9 polymorph occurred in the interval of sulfur composition 0.1≤y≤0.6. This substitution generates a linear dwindling of the unit cell volume. The decomposition of all substituted samples started above 900 °C with a total weight loss linearly dependent on the sulfur content. Electrical studies confirmed that substituting S6+ for Mo6+ suppresses the phase transition of La2Mo2O9 and stabilizes the cubic polymorph down to ambient temperature. It was also remarkable that this substitution caused a decrease in the conductivity, and unfortunately, none of the tested compositions allowed exceeding the conductivity of La2Mo2O9. Infrared and Raman spectra confirmed the presence of the characteristic peaks of sulfates and molybdates groups. 相似文献