Coupled-wave model for square-lattice photonic-crystal lasers with TE polarization -- a general approach

A general coupled-wave model is presented for square-lattice photonic crystal (PC) lasers with transverse-electric polarization. This model incorporates the high-order coupling effects that are important for two-dimensional PC laser cavities and gives a general and rigorous coupled-wave formulation for the full three-dimensional structures of typical laser devices. Numerical examples based on our model are presented for PC structures with different air-hole shapes. The accuracy of the results obtained is verified using three-dimensional finite-difference time-domain simulations

K+-Cl- Cotransporter-3a Up-regulates Na+,K+-ATPase in Lipid Rafts of Gastric Luminal Parietal Cells*

Gastric parietal cells migrate from the luminal to the basal region of the gland and they gradually lose acid secretory activity. So far, distribution and function of K+-Clcotransporters (KCCs) in gastric parietal cells have not been reported. We found that KCC3a but not KCC3b mRNA was highly expressed and KCC3a protein was predominantly expressed in the basolateral membrane of rat gastric parietal cells located in the luminal region of the glands. KCC3a and Na+,K+-ATPase α1-subunit (α1NaK) were co-immunoprecipitated and both of them were highly localized in a lipid raft fraction. The ouabain-sensitive K+-dependent ATP-hydrolyzing activity (Na+,K+-ATPase activity) was significantly inhibited by a KCC inhibitor (DIOA). The stable exogenous expression of KCC3a in LLC-PK1 cells resulted in association of KCC3a with endogenous α1NaK and it recruited α1NaK in lipid rafts, accompanying increases of Na+,K+-ATPase activity and ouabain-sensitive Na+ transport activity which were suppressed by DIOA, while the total expression level of α1NaK in the cells was not significantly altered. On the other hand, the expression of KCC4 induced no association with α1NaK. In conclusion, KCC3a forms a functional complex with α1NaK in the basolateral membrane of luminal parietal cells and it up-regulates α1NaK in lipid rafts, while KCC3a is absent in basal parietal cells

Coupled-Wave Theory for Square-Lattice Photonic Crystal Lasers With TE Polarization

We present a coupled-wave analysis for square-lattice photonic crystal lasers with transverse electric polarization. A model consisting of eight plane waves coupled by Bragg diffraction is used to describe two-dimensional optical coupling. The resonant frequencies and threshold criteria for the modes of oscillation have been determined for the case of index periodicity with a lattice of circular holes. The spatial intensity distributions of these resonant modes have also been calculated. For the fundamental modes, we have investigated how the intensity distribution varies as a function of coupling strength. The dependence of the threshold gain of these modes on hole size has also been elucidated. This semianalytical approach provides a comprehensive understanding of square-lattice photonic crystal lasers and allows more effective optimization of their cavity design

Higher-order vector beams produced by photonic-crystal lasers

We have successfully generated vector beams with higher-order polarization states using photonic-crystal lasers. We have analyzed and designed lattice structures that provide cavity modes with different symmetries. Fabricated devices based on these lattice structures produced doughnut-shaped vector beams, with symmetries corresponding to the cavity modes. Our study enables the systematic analysis of vector beams, which we expect will lead to applications such as high-resolution microscopy, laser processing, and optical trapping