We demonstrated the improvements of an optical biosensor system using a long range surface plasma resonance technique. As preliminary simulation results, we present the prism-based biosensor system with a broader operating range to improve the sensitivity for a wider the measurable reflective index range and a narrower absorbing peak. This proposed optical biosensor system could be used to implement a compact immunoassay device.
Computer generated holograms are used to create doughnut beams. We use negative-tone inorganic-organic hybrid SiO2: TiO2 glasses to fabricate computer-generated holograms. This sol-gel material enjoys an advantage over materials used in the conventional photoresist-based fabrication techniques in terms of a single-step etching-free process. The doughnut beams may be useful in making laser traps for precision measurements and for Bose-Einstein condensation.