Pengukuran Indeks Biasan Cecair dan Dielektrik Lut Sinar Menggunakan Kaedah Anjakan Alur Laser

Satu kaedah pengukuran indeks biasan cecair dan dielektrik lut sinar secara anjakan alur Gaussian laser dilaporkan. Pengukuran indeks biasan air suling, asiton, kaca dan perspek dilakukan pada suhu bilik 21 0 C, denganjarak gelombang laser BeNe (5mW), 632.8 nm. Nilai-nilai indeks biasan direkodkan masing-masing sebagai; 1.333, 1.341, 1.537 dan 1.476. Pengukuran profil alur Gaussian laser dilakukan dengan kaedah anjakan pinggir mata pisau. Kaedah ini boleh digunakan untuk mengukur indeks biasan dari jarak gelombang UV hingga jarak gelombang infra merah dan boleh diubah suai untuk beroperasi secara automatik dengan kawalan komputer

Collimated directional emission from a peanut-shaped microresonator

Collimated directional emission is essentially required an asymmetric resonant cavity. In this paper, we theoretically investigate a type of peanut-shaped microcavity which can support highly directional emission with the emission divergence as small as 2.5o. The mechanism of the collimated emission is explained with the short-term ray trajectory and the intuitive lens model in detail. Wave simulation also confirms these results. This extremely narrow divergence of the emission holds a great potential in highly collimated lasing from on-chip microcavities

Broadband opto-mechanical phase shifter for photonic integrated circuits

A broadband opto-mechanical phase shifter for photonic integrated circuits is proposed and numerically investigated. The structure consists of a mode-carrying waveguide and a deformable non-mode-carrying nanostring, which are parallel with each other. Utilizing the optical gradient force between them, the nanostring can be deflected. Thus the effective refractive indices of the waveguide is changed with the deformation, and further causes a phase shift. The phase shift under different geometry sizes, launched powers and boundary conditions are calculated and the dynamical properties as well as the thermal noise's effect are also discussed. It is demonstrated that a $\pi$ phase shift can be realized with only about 0.64 mW launched power and 50 $\mu m$ long nanostring. The proposed phase shifter may find potential usage in future investigation of photonic integrated circuits

2-Amino-1H-benzoimidazol-3-ium 4,4,4-trifluoro-1,3-dioxo-1-phenyl­butan-2-ide

In the title compound, C7H8N3 +·C10H6F3O2 −, 1H-benzoimidazol-2-amine system adopts a planar conformation with an r.m.s. deviation of 0.0174 Å. The cation and anion in the asymmetric unit are linked by N—H⋯O hydrogen bonds. There are also additional inter­molecular N—H⋯O hydrogen bonds and π–π stacking inter­actions between the phenyl rings of neighbouring anions with centroid–centroid distances of 4.0976 (13) Å