Built-in Alignment Research Articles

Thermocapillary Multidewetting of Thin Films

ABSTRACTThermocapillary dewetting of liquids and molten films has recently emerged as a viable alternative to conventional microprocessing methods. As this thermal gradient-induced mechanism is universal, it can be applied to any material. This work explores the sequential dewetting of materials with varying melting points, including polymers and metals, to create aligned morphologies. The variation in melting point allows for the dewetting of single layers at a time or mobility-limited simultaneous dewetting. As a result, a variety of multimaterial structures can be produced with built-in alignment, such as arrays of concentric circles, lines with periodic segmentation, or islands on holes. This approach employs photothermal methods to induce the necessary thermal gradient, manipulating several variables in order to influence the consequent structures. Adjusting laser power and light intensity allows for the control of temperature for selective dewetting of films; altering beam size and exposure time affects the extent of dewetting in terms of diameter size; overlap effects and simultaneous dewetting can result in complex architectures. This controlled writing of patterns also presents a technique to create both masks at low temperatures for conductive multilayers as well as templates for electrospray deposition.

CMView: Interactive contact map visualization and analysis

Contact maps are a valuable visualization tool in structural biology. They are a convenient way to display proteins in two dimensions and to quickly identify structural features such as domain architecture, secondary structure and contact clusters. We developed a tool called CMView which integrates rich contact map analysis with 3D visualization using PyMol. Our tool provides functions for contact map calculation from structure, basic editing, visualization in contact map and 3D space and structural comparison with different built-in alignment methods. A unique feature is the interactive refinement of structural alignments based on user selected substructures. CMView is freely available for Linux, Windows and MacOS. The software and a comprehensive manual can be downloaded from http://www.bioinformatics.org/cmview/. The source code is licensed under the GNU General Public License.

Monolithic achromatic nulling interference coronagraph: design and performance

We present the design of the monolithic achromatic nulling interference coronagraph (MANIC), a nulling interferometer consisting of optically contacted prisms and a symmetric beam splitter. The optic is designed to enable the direct detection of nearby Jupiter-like exoplanets, and may be extended to enable Earth-like system detection. The monolithic nature of the optic improves on the current state-of-the-art in nulling interferometers by providing built-in alignment and stability, as well as a reduction in size and mass. These qualities make the MANIC extremely robust and simple to integrate, and an excellent candidate for space-based applications.

InGaAsP/InP buried-heterostructure lasers with concurrent fabrication of the stripes and mirrors

Concurrent fabrication of InGaAsP/InP buried-heterostructure laser stripes and mirrors has been demonstrated by the use of dry etching and mass transport. In comparison to previous processes in which the laser stripes and mirrors are fabricated separately, this process offers the advantages of simplicity, built-in alignment, and improved control of device dimensions. Lasers with a cylindrical and a flat end mirror have threshold currents as low as 22 mA and differential quantum efficiencies as high as 24% per facet. Beam divergences as narrow as 13° are obtained for the cylindrical mirrors.