Patent ID: 7492978
Filing Date: 2009-02-17
Classification: G01N,G02B

Abstract:
1. A waveguide structure for detecting particles comprising a sensing layer of a medium disposed upon a second layer having a refractive index ranging from 1.33 to 1.45, said second layer being disposed upon a third layer of refractive index higher than that of the second layer, the structure being capable of supporting a bulk optical mode in the second layer, the medium being adapted to trap a target particle having a diameter ranging from 1 to 10 μm that results in a change in an optical property of the sensing layer and the thickness and/or refractive index of the second layer being such that when light is incident the upper surface of the third layer the optical mode generated in the second layer penetrates into the sensing layer so as to overlap at least a major portion of the particle.