We report on the first experimental demonstration of resonant optical trapping of dielectric particles in a two-dimensional hollow photonic crystal cavity. The cavities are implemented in an optofluidic chip consisting of a silicon-on-insulator substrate and an ultrathin microfluidic membrane, Resonant optical trapping of 500 nm polystyrene beads is achieved using less than 120 μW optical power in the cavity for trapping times reaching over ten minutes.
We present a projection optical system incorporating a dynamic optical element and we outline some of its
potential applications for digital projection displays. We describe experiments undertaken to validate one of
these applications, the correction aberrations in a rear-projection television (RPTV) optical module where the
original fold mirror is replaced by a simple MEMS deformable mirror.
We present a projection optical system incoporating a dynamic optical element and we outline some of its potentional applications for digital projections. We describe experiments undertaken to validate a variety of these applications, in particular: change of focus without mechanical motion of the focus group; correction of chromatic aberration; and correction of a variety of other aberrations. We conclude that dynamic optical element can be used to improve the quality of image achieved from a very simple digital projection optical system.
FPGA (Field Programmable Gate Array) technology has become a very powerful tool available to the electronic designer, specially after the spreading of high quality synthesis and simulation software packages at very affordable prices. They also offer high physical integration levels and high speed, and eases the implementation of parallelism to obtain superb features. Adaptive optics for the next generation telescopes (50-100 m diameter) -or improved versions for existing ones- requires a huge amount of processing power that goes beyond the practical limits of today's processor capability, and perhaps tomorrow's, so FPGAs may become a viable approach. In order to evaluate the feasibility of such a system, a laboratory adaptive optical test bench has been developed, using only FPGAs in its closed loop processing chain. A Shack-Hartmann wavefront sensor has been implemented using a 955-image per second DALSA CA-D6 camera, and a 37-channel OKO mirror has been used for wavefront correcting. Results are presented and extrapolation of the behavior for large and extremely large telescopes is discussed.