Electroclinic effects in a homogeneously aligned smectic A cell

The electroclinic effect, in a material having a first order S_A to S_C* transition, is studied using the half leaky guided mode geometry. Using an approximately 1 μm thick, homogeneously aligned cell, the voltage induced director twist is characterized at a few temperatures in the S_A phase. The mean field theory readily explains the data recorded at low fields where a linear dependence on voltage is found. However, at higher fields, an unexpected saturation occurs which is most likely caused by the influence of strong surface anchoring forces.     

Laser action in CdS by optical pumping with radiation from a CO2 laser-produced plasma

Radiation from a CO₂ laser-produced plasma has been used to produce laser action in CdS at 5260 Å. This technique compares favorably with optical pumping of CdS by 3371 Å radiation from a pulsed N₂ laser and its potential as a new source for the optical pumping of solids at short wavelengths is strongly indicated.     

Amplitude-distribution analysis of acoustic emission

Amplitude distribution of acoustic-emission events generated during fracture of materials contains the potential information about the fracture mechanisms. A methodology is developed for the analysis of acousticemission burst signals. Based on this, the amplitude distributions can be characterized from the cumulative counts and events data alone. This simplifies the equipment as well as the data analysis. A model for amplitude distribution is proposed here, which can potentially identify two mechanisms operating simultaneously. It is also shown analytically that cumulative counts (N) are linearly related to summation of amplitudes of events and thatN can be considered a measure of the total energy of acoustic emission only if the amplitude distribution does not change significantly.