A novel retroreflector design using a pseudo-phase-conjugation mirror, viz., a corner cube mirror array (CMA), is proposed for light-collecting systems to increase the apparent brightness of the light source and thus increase the light collection efficiency. Measurement data for a dual paraboloid reflector system using a CMA retroreflector are presented. Design issues for the CMA are discussed. The advantages of the CMA retroreflector are: (1) it is a self-aligning technique, so it works regardless of its shape and position; (2) it is self-compensated for image distortion. Therefore a highly efficient low-cost light collection system with bigger manufacture tolerances is possible.
Dual paraboloidal reflectors (DPR) can couple more light into small etendue projection systems. The imaging property of DPRs at two conjugation focal points and their peripheral areas has been investigated using ASAP simulation and observation. The result confirms that the DPR can produce one to one image at the conjugated focal points, which is the reason why dual parabolic reflectors are beneficial. In the periphery area, the image is distorted. The image distortion was analyzed theoretically and the results agree with observation. This imaging property was used to develop a new method of locating the focal points of DPRs accurately. A new lamp manufacturing procedure and a pilot line were setup and tested. The coupled lumen efficiency has been increased by 13%.
Twelve lithium niobate crystals doped with Ce, Co, Cr, Cu, Fe, Mn, Ni, Rh, Tb, Fe:Ce, Fe:Cr, and Fe:Mn have been grown and tested. The transmission spectra and dark conductivity of the crystals are presented. Holograms have been written in each of the crystals with wavelengths from 457 nm to 671 nm. The quality and stability of the holograms vary dramatically among the crystals. The properties of the holograms and a comparison of sensitivities between the crystals are discussed.
An optoelectronic smart pixel device for optically reconfigurable Boolean logic gate array is proposed. It consists of more than 4 X 10<SUP>5</SUP> pixels used as logic gates that can operate in parallel. By setting different optical biases on pixels, every pixel is reconfigurable (to perform different kinds of logic gate operations). All kinds of logic gates can be implemented simultaneously in this device. The principle of operation and its fundamental characteristics are described in detail. The device makes fully use of the physics features of amorphous silicon photoconductor and liquid crystal and does not need the controlling architecture with very large scale integration circuits. Therefore, bigger aperture ratio, higher resolution (more than 45 lines/mm), and higher space bandwidth product are achievable.
A novel method of generating optical phase conjugation using an azo-doped liquid crystal valve is proposed for the first time. Its response time, diffraction efficiency, and threshold intensity are measured. The resolution of the device is discussed. An observation of diffraction rings caused by self-phase modulation when a low-power laser beam passes through the azo-doped liquid crystal valve is reported. Finally, these phenomena are shown to be results of the reorientation of liquid crystal molecules driven by the photoinduced isomerization, not merely an azo dye effect or a local heating effect.