ABSTRACT
We present a theoretical discussion and experimental demonstration of what to our knowledge is a novel integrated electro-optic lens and beam deflector fabricated in lithium tantalate. The cylindrical lens collimates Gaussian beams as small as 4 mum in diameter, whereas the independently controlled deflector is capable of scanning the collimated beam through an angular range of nearly 20 degrees .
ABSTRACT
We report on a horn-shaped electro-optic scanner based on a ferroelectric LiTaO(3) wafer that is capable of scanning 632.8-nm light by an unprecedented 14.88 degrees angle for extraordinary polarized light and by 4.05 degrees for ordinary polarized light. The device concept is based on micropatterning ferroelectric domains in the shape of a series of optimized prisms whose refractive index is electric field tunable through the electro-optic effect. We demonstrate what we believe is a novel technique of using electro-optic imaging microscopy for in situ monitoring of the process of domain micropatterning during device fabrication, thus eliminating imperfect process control based on ex situ monitoring of transient currents.
ABSTRACT
We have measured the rise time of laser-generated shock waves in vapor plated metal thin films using frequency-domain interferometry with subpicosecond time resolution. 10%- 90% rise times of <6.25 ps were found in targets ranging from 0.25 to 2.0 microm in thickness. Particle and average shock velocities were simultaneously determined. Shock velocities of approximately 5 nm/ps were inferred from the measured free surface velocity, corresponding to pressures of 30-50 kbar. Thus, the shock front extends only a few tens of lattice spacings.
ABSTRACT
We report what we believe to be the first stand-alone integrated electro-optic lens and scanner fabricated on a single crystal of Z-cut LiTaO(3). The independently controlled lens and scanner components consist of lithographically defined domain-inverted regions extending through the thickness of the crystal. A lens power of 0.233 cm(-1) kV(-1) and a deflection angle of 12.68 mrad kV(-1) were observed at the output of the device.
ABSTRACT
We demonstrate three-dimensional trapping of low-index particles (20-microm-diameter hollow glass spheres in water) by using a single, strongly focused, stationary dark optical vortex laser beam. The holographically generated vortex, which is similar to a TEM(01)* mode beam, was also used to trap and form ring patterns of high-index particles.
ABSTRACT
A measurement technique is described in which the radiative quantum efficiency of certain transitions in rare-earth-doped glasses can be determined based only on relative fluorescence measurements. We calibrate the emission from the level of interest by measuring emission into that level from a higher excited level. Application of the technique to Pr(3+)-doped sulfide glasses yields quantum efficiencies for the (1)G(4) ? (3)H(5) transition as high as 60%, in good agreement with measurements using the integrating sphere technique. Calculated efficiency values based on the Judd-Ofelt technique are shown to be subject to inherent uncertainties.