Precise autofocus method employing normalized fluorescence image size in a two-photon polymerization nanofabrication system.

The autofocus method has been investigated to improve the precise positioning of a substrate surface at the center of the laser focal spot in two-photon polymerization (TPP) nanofabrication. For this purpose, we developed a novel autofocus method using normalized image size, which was calculated with the second momentum radius (SMR) of two-photon induced fluorescence (TPIF). The SMR of TPIF was theoretically analyzed and experimentally compared with the average intensity of TPIF for various input laser powers.

Improvement of range precision in laser detection and ranging system by using two Geiger mode avalanche photodiodes.

In this paper, the improvement of range precision in a laser detection and ranging (LADAR) system by using two Geiger mode avalanche photodiodes (GmAPDs) is described. The LADAR system is implemented by using two GmAPDs with a beam splitter and applying comparative process to their ends. Then, the timing circuit receives the electrical signals only if each GmAPDs generates electrical signals simultaneously.

Autofocusing method using fluorescence detection for precise two-photon nanofabrication.

We propose a method capable of focusing a laser beam on a substrate automatically via fluorescence detection from the resin of a two-photon nanofabrication system. When two-photon absorption (TPA) occurs by focusing the laser beam in the resin, fluorescence is emitted from the focusing region in the visible range. The total pixel number above the threshold value of the fluorescence images obtained by a CCD camera is plotted on a graph in accordance with the focus position.

A simple and smart telemedicine device for developing regions: a pocket-sized colorimetric reader.

We have proposed a novel mobile healthcare platform, combining a pocket-sized colorimetric reader (13.5 × 6.5 × 2.