Evanescently-coupled hybrid III-V/silicon laser based on DVS-BCB bonding

© 2014 IEEE. Controllable electrical breakdown of multiwall nanotubes (MWNTs) is studied utilizing the atomic force microscopy (AFM). Electrical breakdown has been known as the way to fundamentally understand the electrical properties of nanotubes and an approach to develop MWNT based transistors and sensors. Normally, electrical breakdown was known to be happened in the center of MWNT because of the thermal accumulation. However, considering the effect of thermal dissipation, the electrical breakdown could be mechanically controlled by an additional heat sink, which could be the substrate of MWNT device. Therefore, the electrical breakdown process is controllable through controlling Joule heating and thermal dissipation. In this research, we study the crucial factors that affect the electrical breakdown. The AFM based nano robot is used to measure the conductance distribution, and manipulate the three dimensional structure of MWNT in order to change the position of heat sink to control the location where electrical breakdown happened. The controllable electrical breakdown is an alternative approach for conducting bandgap engineering in nanodevice and fabricating high performance nano sensors and transistors.Link_to_subscribed_fulltex

Hybrid III-V/Si distributed-feedback laser based on adhesive bonding

A hybrid evanescently coupled III-V/silicon distributed-feedback laser with an integrated monitor photodiode, based on adhesive divinyl siloxane-benzocyclobutene bonding and emitting at 1310 nm, is presented. An output power of similar to 2.85 mW is obtained in a continuous wave regime at 10 degrees C. The threshold current is 20 mA and a sidemode suppression ratio of 45 dB is demonstrated. Optical feedback is provided via corrugations on top of the silicon rib waveguide, while a specially developed bonding procedure yields 40-nm-thick adhesive bonding layers, enabling efficient evanescent coupling

Groups with many abelian subgroups

AbstractIt is known that a (generalized) soluble group whose proper subgroups are abelian is either abelian or finite, and finite minimal non-abelian groups are classified. Here we describe the structure of groups in which every subgroup of infinite index is abelian

Evaluation of the two-photon exchange diagrams for the (1s)22p3/2(1s)^2 2p_{3/2} electron configuration in Li-like ions

We present ab initio calculations of the complete gauge-invariant set of two-photon exchange graphs for the $(1s)^2 2p_{3/2}$ electron configuration in Li-like ions. These calculations are an important step towards the precise theoretical determination of the $2p_{3/2}$-$2s$ transition energy in the framework of QED.Comment: 17 pages, 6 figure