Lifelink: 3G-based mobile telemedicine system.

Current wired telemedicine systems encounter difficulties when implemented in archipelagic developing countries because of the high cost of fixed infrastructure. In this research, we devised Lifelink, a mobile real-time telemonitoring and diagnostic facility to command and control remote medical devices through mobile phones. The whole process is phone-based, effectively freeing offsite medical specialists from stationary monitoring consoles and endowing the system with the potential to increase the number participating consultants.

Phase determination in interference-based superresolving microscopes through critical frequency analysis.

Utilizing the interference of wave fronts of two opposing lenses, 4Pi-confocal and I(5)M microscopy improve the axial resolution of far-field fluorescence microscopy as much as threefold to sevenfold. However, establishing the phase difference of the wave fronts in the sample is a problem yet to be solved. Here we show that the phase difference is encoded in the microscope's transfer of the spatial frequencies that match the distance of the interference peaks.

Fault localization and analysis in semiconductor devices with optical-feedback infrared confocal microscopy.

We report on a cost-effective optical setup for characterizing light-emitting semiconductor devices with optical-feedback confocal infrared microscopy and optical beam-induced resistance change. We utilize the focused beam from an infrared laser diode to induce local thermal resistance changes across the surface of a biased integrated circuit (IC) sample. Variations in the multiple current paths are mapped by scanning the IC across the focused beam.

Wide-field depth-sectioning fluorescence microscopy using projector-generated patterned illumination.

We present a simple and cost-effective wide-field, depth-sectioning, fluorescence microscope utilizing a commercial multimedia projector to generate excitation patterns on the sample. Highly resolved optical sections of fluorescent pollen grains at 1.9 microm axial resolution are constructed using the structured illumination technique.

Tracking the emergence of defect in light emitting semiconductor diodes with two-photon excitation microscopy and spectral microthermography.

We demonstrate a multifunctional optical technique for tracking the evolution of defects in live 605 nm LEDs. Photocurrent images, electroluminescence, and spectral reflectance maps are simultaneously acquired and utilized to evaluate LED performance at different injection currents. Free-carrier density profiles in the active region are constructed from photocurrent images that are generated via two-photon excitation (2PE) at 800 nm.

High-resolution mapping of quantum efficiency of silicon photodiode via optical-feedback laser microthermography.

We map the external quantum efficiency (QE) distribution of a silicon photodiode (PD) sample via a thermographic imaging technique based on optical-feedback laser confocal microscopy. An image pair consisting of the confocal reflectance image and the 2D photocurrent map is simultaneously acquired to delineate the following regions of interest on the sample: the substrate, the n-type region, the pn overlay, and the bonding pad. The 2D QE distribution is derived from the photocurrent map to quantify the optical performance of these sites.

Spectral microthermography for component discrimination and hot spot identification in integrated circuits.

We demonstrate an efficient and versatile spectral microthermography technique for identifying hot and cold spots in the active layer of a biased integrated circuit. Hot (cold) spots are regions where heat accumulates more rapidly (slowly) than the average rate of the entire active layer. Knowledge of the hot and cold spot locations is crucial in assessing the thermal integrity of a layer structure because hot spots are locations were defects are more likely to develop.

High-contrast microscopy of semiconductor and metal sites in integrated circuits by detection of optical feedback.

High-contrast microscopy of semiconductor and metal sites in integrated circuits is demonstrated with laser-scanning confocal reflectance microscopy, one-photon (1P) optical-beam-induced current (OBIC) imaging, and detection of optical feedback by means of a commercially available semiconductor laser that also acts as an excitation source. The confocal microscope has a compact in-line arrangement with no external photodetector. Confocal and 1P OBIC images are obtained simultaneously from the same focused beam scanned across the sample plane.