Laser beam deflection sensor as a detector for high-efficiency chromatography

1986 ◽  
Vol 58 (1) ◽  
pp. 243-246 ◽  
Author(s):  
Janusz. Pawliszyn
Keyword(s):  
Laser Beam ◽  
High Efficiency ◽  
Beam Deflection

Scanning Capacitance Microscopy of Dopants in III-V Semiconductors

1998 ◽  
Vol 4 (S2) ◽  
pp. 640-641
Author(s):  
David V. Lang
Keyword(s):  
Quantum Well ◽  
Laser Beam ◽  
Surface Topography ◽  
Cross Sections ◽  
Beam Deflection ◽  
Doping Analysis ◽  
Scanning Capacitance Microscopy ◽  
Sample Spacing ◽  
Doping Profiles ◽  
Multi Quantum Well

Scanning Capacitance Microscopy (SCM) was first developed in 1985 as a method for sensing tip-to-sample spacing for surface topography profiling in connection with the RCA VideoDisc. Williams and coworkers were the first to use an SCM for obtaining dC/dV doping profiles in semiconductors, albeit with a rather modest resolution of 200 nm. More recently, it has been developed as a 50-nmresolution tool for microscopic doping analysis of semiconductors by measuring the tip-to-sample rf capacitance in an AFM controlled by other means, e.g. by laser beam deflection of a cantilever tip. In this paper we report on the application of SCM to study the 2D doping profiles of InP-based devices, such as multi-quantum well lasers.It is particularly convenient to prepare cross sections of III-V devices, since the material readily cleaves on [110] planes, as compared to silicon where cross sections must be obtained by painstaking polishing.

A Simple Co-Rotational Finite Planar Beam Element of Geometrical and Material Nonlinearity

2012 ◽  
Vol 268-270 ◽  
pp. 1163-1167
Author(s):  
Song Bai Cai ◽  
Da Zhi Li ◽  
Chang Wan Kim ◽  
Pu Sheng Shen
Keyword(s):  
Stiffness Matrix ◽  
High Efficiency ◽  
Beam Theory ◽  
Yield Function ◽  
Beam Element ◽  
Transformation Matrix ◽  
Material Nonlinearity ◽  
Beam Deflection ◽  
Nodal Force ◽  
Tangential Stiffness

A simple geometrical and material nonlinear co-rotational planar beam element of field consistency is proposed. Herein the element which produces a local stiffness matrix of 3 by 3 other than 6 by 6 is developed. Material nonlinearity is taken into account on the base of yield function of element internal forces. By applying static equilibrium relationship of classic beam theory for the transferring of local element nodal force to global element nodal force, a new transformation matrix different from the nodal displacement transformation matrix is established. Although this results in an asymmetric global tangential stiffness matrix, the new transformation is simpler, and gives rise to field consistency and makes it possible to compute very large beam deflection without remeshing of the deformed structure. Computations of numerical example indicates that formulations for the nonlinear beam element are of validation and high efficiency

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