Optical detector technology has progressed to the point where it has single photon counting capability. It is theoretically possible for optical diagnosis to achieve enough sensitivity to detect a single molecule. Unfortunately, the highly scattering nature of biological samples and the highly diffractive (or reflective) nature of optical elements create very serious noise and background problems, especially for the low signal intensity regime. To alleviate this problem, Physical Optics Corporation (POC) proposes to continue the development of a special holographic noise suppressing coating technology, analogous to moth-eye structures, which significantly improves photon detection sensitivity. During Phase I of this project, POC successfully demonstrated the feasibility and versatility of these coatings, and showed that they can be applied to almost any internal part of an optical detection system, improving sensitivity by up to a factor of 10. Novelty features of POC's moth-eye based technology include the following: l) Thin holographic films act as highly effective light-traps; 2) Films have high transparency when acting as antireflection coatings; 3) Films have significantly enlarged surface area due to their surface relief; and 4) Randomized moth-eye structures act as a diffuser that will homogenize incoming light into a controlled spatial pattern.
POC's low cost moth-eye coating technology, with mass-production potential, offers significantly improved sensitivity, enhancing the detection of weak optical signals. Depending on the design of the surface relief structure, moth-eye based foils can have various novel properties. In particular, the moth-eye foil will be implemented in flow cytometry (to reduce stray light), solid phase immunoassay (to sense surface enhancements), endoscopy (to produce uniform illumination), photometry and spectrometry (to reduce light scattering).
