High-efficiency micro-optical color filter for liquid-crystal projection system applications.

High-efficiency color filters composed of a microprism array, optical interference color filters, and a microlens array light compressor were developed to increase the optical throughput of liquid-crystal projection systems. The new devices utilize the energy of whole spectra by taking full advantage of a light compressor and interference dichroic filters to distribute the energy of spectra to the respective color pixel area. Thus high-efficiency micro-optical color filters allow efficient utilization of the energy of incident light and maximize the optical throughput of the projection system.

Design of illumination and projection optics for projectors with single digital micromirror devices.

We present a new optical system design for a projector with a single digital micromirror device (Texas Instruments Digital Micromirror Device) that improves on previous designs in terms of optical efficiency, uniformity, and contrast while yielding a low-profile and compact system. A rod integrator is incorporated with a compact relay system to maximize light efficiency and to increase illumination uniformity. The uniformity achieved by the optimized optical system was calculated to be 94%. In addition, this unique light-separator design has dual output channels to increase the image contrast by steering the off-state light away from the projection lens. This projector design provides very efficient light utilization, and we discuss how the geometrical optical efficiency of the system can be boosted to approach the theoretical maximum.

Interlayer cross talk in dual-layer read-only optical disks.

Volumetric optical disks comprising multiple data layers have been proposed to multiply recording density. Owing to the presence of out-of-focus data layers, interlayer cross talk is induced in readout. An optical model was developed to study the readout process and the effect of interlayer cross talk on the readout of dual-layer read-only optical disks. Schemes to improve the readout characteristics by suppression of the interlayer cross talk were proposed. Experiments that agreed well with the simulation resulted.

Pulse-read on erasable thermal phase-change superresolution disks.

New erasable thermal phase-change superresolution (EPSR) disks composed of mask and recording layers can increase recording density by the detection of the below-diffraction-limited marks within the readout spot. The formation of the aperture and the readout signal on the EPSR disk were analyzed. The feasibility of optically designed EPSR disks was evaluated by thermal simulation. A carrier-to-noise ratio of 32 dB at a mark size of 0.4 mum, 8 dB higher than that of a conventional disk, was obtained by application of a pulse-read method to the EPSR disks at a wavelength of 780 nm and a numerical aperture of 0.55.