Fringe projection techniques: Whither we are?

Femtosecond two-photon direct laser writing is used to create 100-µm-scale high-performance multi-lens objectives.

Two-photon direct laser writing of ultracompact multi-lens objectives

We introduce the concept of the perfect optical vortex whose dark hollow radius does not depend on the topological charge. It is shown analytically and experimentally that such a vortex can be approximately generated in the Fourier transforming optical system with a computer-controlled liquid-crystal spatial light modulator.

Generation of the "perfect" optical vortex using a liquid-crystal spatial light modulator

Real-time structured light profilometry: a review

Two of the recent major research topics in optoelectronic devices are discussed: the development of new organic materials (both molecular and polymeric) for the active layer of organic optoelectronic devices (particularly organic light-emitting diodes (OLEDs)), and light management, including light extraction for OLEDs and light trapping for organic solar cells (OSCs). In the first section, recent developments of phosphorescent transition metal complexes for OLEDs in the past 3–4 years are reviewed. The discussion is focused on the development of metal complexes based on iridium, platinum, and a few other transition metals. In the second part, different light-management strategies in the design of OLEDs with improved light extraction, and of OSCs with improved light trapping is discussed.

Recent advances in transition metal complexes and light-management engineering in organic optoelectronic devices.

A fast and efficient technique for profilometric measurement using color-coded grating is proposed. Four colors are used to code the grating and each color represents only one logical state. There are 48 stripes in one period of the color grating, which is large enough for normal measurement. As compared with the previous techniques, it has the advantages of simple hardware without moving mechanical part, single exposure for obtaining 3D information, little influence of the noise and the 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.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Color-coded grating 3D profile measurement and its application

Elemental image array self-calibrating method in array type optical acquisition of three-dimensional scene information

A color-coded projection grating is used to provide means of measuring 3D surface profiles. In conventional 24 bits RGB model, each color has 256 gray levels, whereas we use only the levels of 0 and 255 to maximize the difference of gray levels. Thus there are eight colors which can be used to code the grating. They are white, red, green, blue, cyan, magenta, yellow, and black. In order to get a large space period grating, we code the grating on a specific order. If we use eight kinds of colors to code the grating, we can get 64 strips in one period. In this case the space period of the projection grating is large enough in the most of measurement of surface profiles. Only one image is needed in 3D measurement and so it is suitable for on-line inspection. In our system the measurement error is less than +/- 1.3 mm.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Zhiliang Fang

Papers

Color-coded grating 3D profile measurement and its application

Elemental image array self-calibrating method in array type optical acquisition of three-dimensional scene information

Novel surface profile measurement with color-coded grating projection