A fast and efficient technique for profilometric measurement with a color-coded grating is proposed. Eight colors are used to code the grating, and each color represents only one logical state. There are 64 stripes in one period of the color grating, which is large enough for normal measurement. Compared with the previous techniques, it has the advantages of simple hardware without moving mechanical parts, single exposure for obtaining three-dimensional information, little influence from noise and from nonlinearity of the CCD camera on the measurement accuracy, and higher anti-color-blurring capability. The suggested technique is suitable for on-line inspection and dynamic measurement of moving objects.

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We propose a generalized approach to producing optical vortices with suppressed sidelobes using a variable Bessel-like function added to the conventional spiral phase plate. Experimental verifications are implemented by a phase-only spatial light modulator. It is demonstrated that the method is valid for optical vortex beams with arbitrary topological charges and without changing the primary ring size as a unique property among the existing techniques.

We propose a method for enhancing depth-of-field, in which the spot size on a marginal depth plane is reduced. This method is implemented in a projection-type integral imaging system using a negative lens array without a diffuser. Numerical simulation results show that the spot size is merely 5.7% of that in a conventional system. Thus, the depth-of-field in the proposed system is enhanced by 17.5 times over that in a conventional system. Optical experiments confirm good agreement between the results and numerical predictions.

An illumination system using LED sources for pocket-size projectors is designed. Its color gamut is much larger than the sRGB standard. The maximum theoretical efficiency of this system is 29.98% by non-imaging theory-based calculations. To analyze the system model, 1.5 x 10(6) rays are traced by using the LightTools software. The total light flux that illuminates the digital micromirror device is 44 lm and the American National Standards Institute 13-point uniformity on the surface is 91.55%, -91.15% with a system efficiency of 28.3%. The calculations are in good agreement with the simulation results. The illumination system can be used for personal pocket-size projectors providing a 15-20 in. (38-51 cm) color display with the brightness comparable with a laptop.