Abstract
A retroreflective imaging system for imaging microscopic targets over macroscopic sampling areas is introduced. Detection of microorganism-bound retroreflector (RR) targets across millimeter-scale samples is implemented according to retroreflection directionality, collimation, and contrast design characteristics. Retroreflection directionality is considered for corner-cube (CC) and spherical geometries. Spherical-RRs improve directionality and reliability. Retroreflection collimation is considered for spherical-RRs. Retroreflective images for micro-CC-RRs and micro-spherical-RRs with varying refractive indices show optimal results for high refractive index BaTiO3micro-spherical-RRs. A differential imaging technique improves retroreflection contrast by 35 dB. High refractive index micro-spherical-RRs and differential imaging, together, can detect microscopic RR targets across macroscopic areas.
Original language | English (US) |
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Pages (from-to) | 3647-3655 |
Number of pages | 9 |
Journal | Applied Optics |
Issue number | 17 |
DOIs | |
State | Published - Jun 10 2014 |
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Engineering (miscellaneous)
- Electrical and Electronic Engineering