Polymer gratings based on photopolymerization for low-order distributed feedback polymer lasers

Novel polymer distributed feedback(DFB)gratings are fabricated based on photopolymerization to reduce lasing threshold of polymer lasers.A photopolymer formulation sensitive to 355-nm ultraviolet(UV)light is proposed for the fabrication of polymer gratings and it can be used to form polymer films by spin-coating process.A very low surface-relief depth ranging from 12.5 to about 1.0 nm has been demonstrated with a refractive-index modulation of about 0.012.The experimental results indicate that such polymer gratings have promising potentials for the fabrication of low-order DFB organic semiconductor lasers.     

大尺寸单晶金刚石制备的研究进展

单晶金刚石在电学,光学方面有着良好的应用前景,已经成为金刚石领域的研究焦点之一.本文论述了大尺寸单晶金刚石的制备方法、生长条件、研究现状以及存在的缺陷,概述了制备单晶金刚石过程中出现的问题并针对部分问题提出改善措施.     

Design and construction of a TPC prototype based on GEM detector readout

A time projection chamber (TPC) readout by gas electron multipliers (GEM) detector is a very promising candidate for the central tracking system of ILC (International Linear Collider). A prototype is designed and set up in our lab and introduced here. The tests during and after the assembly prove that the prototype TPC has been constructed successfully. It is ready for further study.     

Production of the new gauge boson BH via e-γ collision in the littlest Higgs model

The lightest new gauge boson BH with mass of hundreds GeV is predicted in the littlest Higgs model. BH should be accessible in the planned ILC and the observation of such particle can strongly support the littlest Higgs model. The realization of γγ and e-γ collisions would open a wider window to probe BH. Inthis paper, we study the new gauge boson BH production processes e-γ→ e-γBH and e-γ→e-ZBH at the ILC. Our results show that the production cross section of the process e-γ→ e-ZBH is less than 0.1 fb in most parameter spaces allowed by the electroweak precision data while the cross section of the process e-γ→ e-γBH can be over one fb in the favorable parameter spaces. With the high luminosity, the enough typical signals could be produced via e-γ→ e-γBH. Because the final electron and photon beams can be easily identified and the signal can be easily distinguished from the backgrounds produced by Z and H decaying, e-γ→e-γBH is a promising process to probe BH.