The characteristic analysis of traveling wave electrooptic modulators on z-cut and x-cut lithium niobate substrates is carried out by using the finite element method based on a quasi-TEM approximation. The microwave effective index, the characteristic impedance, and the frequency dependent attenuations are calculated. The optical frequency response is also calculated and hence the 3-dB optical ...

We analyze corner-cut square microcavities as alternative planar microcavities. Ray tracing shows open-ray orbits that are 90-degree-rotated can oscillate between each other upon reflections at the 45-degree corner-cut facets, and have the same sense of circulation. Our two-dimensional finite-difference time-domain simulations suggest that a waveguide-coupled corner-cut square microcavity with ...

Substantial variability is seen when thickness measurements using conventional ultrasonic time of flight are carried out on rough surfaces; this makes it difficult to estimate corrosion rates the mechanism leads surface roughness. It has been shown that guided wave cut-off frequencies (through resonance frequencies) can be done at much lower than gauging for same minimum resolution. The frequen...

[1] Traditionally, P wave arrival times have been used to locate regional earthquakes. In contrast, the travel times of surface waves dependent on source excitation and the source parameters and depth must be determined independently. Thus surface wave path delays need to be known before such data can be used for location. These delays can be estimated from previous earthquakes using the cut-an...

In lecture 19, we saw an LP relaxation based algorithm to solve the sparsest cut problem with an approximation guarantee of O(logn). In this lecture, we will show that the integrality gap of the LP relaxation is O(logn) and hence this is the best approximation factor one can get via the LP relaxation. We will also start developing an SDP relaxation based algorithm which provides an O( √ log n) ...

In this study, microstructure evolution at intermetallic interfaces in SnAgCu solder joints of an area array component was investigated at various stages of a thermal cycling test. Failure modes of solder joints were analyzed to determine the effects of process conditions on crack propagation. Lead-free printed-circuit-board (PCB) assemblies were carried out using different foot print designs o...