Optical switching experiment

A solid state, long term optical switching experiment was conducted using ITO coated glass as the substrate and THF/O.IM TBAH as the electrolyte (i.e., same experimental set-up as was used for spectral studies) in order to evaluate the stability of the films to withstand repeated bleach-colour cycling. Polymer 5 was the only material (studied here) to form films stable toward dissolution over the full length of the experiment. Given this, the film ( 0.5 micron in thickness) of polymer 5 on ITO was cycled between -200 mV and 600 mV (i.e., switched electrochemically between the Ru /Ru and Ru /Ru states). The... 

Optofluidic Devices for Light Manipulation and Bio-sensing, Fig. 2 (a-b) Optical experiment pictures of the hydrodynamic tunable optical switching... 

Phase-dependent coherence and interference can be induced in a multi-level atomic system coupled by multiple laser fields. Two simple examples are presented here, a three-level A-type system coupled by four laser fields and a four-level double A-type system coupled also by four laser fields. The four laser fields induce the coherent nonlinear optical processes and open multiple transitions channels. The quantum interference among the multiple channels depends on the relative phase difference of the laser fields. Simple experiments show that constructive or destructive interference associated with multiple two-photon Raman channels in the two coherently coupled systems can be controlled by the relative phase of the laser fields. Rich spectral features exhibiting multiple transparency windows and absorption peaks are observed. The multicolor EIT-type system may be useful for a variety of application in coherent nonlinear optics and quantum optics such as manipulation of group velocities of multicolor, multiple light pulses, for optical switching at ultra-low light intensities, for precision spectroscopic measurements, and for phase control of the quantum state manipulation and quantum memory. 

Figure 15. The experiment of Aspect, Dalibard, and Roger with optical switches. Each switching device (Q, Cn) is followed by two polarizers in two different orientations. The arrangement is equivalent to one in which a single polarizer on each side is switched quickly between two orientations. L = 12 m.

FIGURE 17 Tilt angle measured in x-ray experiment ( ray) nd by optical switching... 

A cost effective experimental setup for optical modulettion experiments, recently built in our laboratory. Is shown in Fig. 8 (57). Similar setup was recently reported by Tian et al. (58). Experiments performed with this system include photoreflectance (PR), electrolyte electroreflectance (EER), surface photovoltage spectroscopy (SPV), 1st. and 2nd. harmonics photoinduced current-voltage characteristics, spectral response and d.c. current-voltage characteristics. One can switch electronically between experiments and perform any number of techniques without moving the cell or removing the electrode from the electrolyte. A variable neutral... 

Our experiments differs from the ideal scheme in another respect the switching are not truly at random, since the acousto-optical switches are driven by quasi-periodic generators. Nevertheless, the two generators on the two sides function in a completely uncorrelated way, especially considering their frequency drifts. 

In an optical pumping experiment the polarization of the atoms in the cell is zero when the pumping lamp is switched on at t=0. Show, by direct substitution in equation (17,8), or otherwise, that the approach to the equilibrium polarization is given by equation (17.9). 

Richard L. Rowe is retired chief executive officer of MCMS, Inc., a 550 million electronics contract manufacturing company. His experience includes sensor technologies applied to aviation security, and his expertise includes new technologies in optics and radio frequency, electronic sensors, and switch products. He has more than 20 years of experience in the electronic sensors and switch products in-... 

Four different types of tasks are performed by automation. Two involve the sequencing of valves and pumps Involved 1n the setup and completion of the designed experiment through the operation of the test and hydraulic fluid systems. The other tasks involve the control of the temperature bath and data collection. To perform these tasks, a1r-actuated solenoids and optically coupled sol Id-state relays are used. These devices are controlled by an electrical circuit consisting of the device connected 1n series with a power supply and a channel on the actuator card In the HP 3497. The power supply 1s either 24 VDC for use with the solenoids or 5 VDC for the solid-state relays. The actuator output channel acts as a simple on/off switch which allows power to be supplied to the solenoid or relay when closed. The logic of the circuit 1s controlled by application programs running on the local HP 1000. 

Using this method, the M6R8/PM6R8 blend showed precisely the behavior expected for the achiral SmAPA structure. Specifically, the optical properties of the films were consistent with a biaxial smectic structure (i.e., two different refractive indices in the layer plane). The thickness of the films was quantized in units of one bilayer. Upon application of an electric field, it was seen that films with an even number of bilayers behaved in a nonpolar way, while films with an odd number of bilayers responded strongly to the field, showing that they must possess net spontaneous polarization. Note that the electric fields in this experiment are not strong enough to switch an antiferroelectric to a ferroelectric state. Reorientation of the polarization field (and director structure) of the polar film in the presence of a field can easily be seen, however. 

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