Ultra Sensitive Bio-Detection Using Whispering Gallery Spheres and Intra-Cavity Polarization Mode Beating (PMB)

如果球体（或腔）的Q值高，则50-200微米量级的回音壁球体必须满足非常尖锐的谐振条件。 如果生物实体通过Si-O-抗原复合物附着到球体上，那么当抗原附着时，回音壁模式看到的有效折射率将有小的变化。 这一设想已被用于灵敏的生物检测。 通过将这样的装置放置在激光腔内，可以不测量与生物实体的附着相关联的波长偏移，而是测量模式拍频偏移。 通过将光域中的测量（波长偏移）转换为RF（射频）域中的测量，即，该奖项由电气和通信系统司和国际科学与工程办公室共同支持。

0423873MorseA Whispering Gallery sphere of the order of 50-200 microns must satisfy a very sharp resonance condition if the Q of the sphere (or cavity) is high. If a biological entity is attached to the sphere through an Si-O-antigen complex, then, when an antigen attaches, there will be a small shift in the effective refractive index that the Whispering Gallery mode(s) sees. This conceit has been used for sensitive biodetection. By placing such a device within a laser cavity, it is possible to measure not a wavelength shift associated with the attachment of the biological entity, but a mode beating shift. By converting a measurement in the optical domain (wavelength shift) to a measurement in the RF (Radio Frequency) domain, i.e., a shift in the mode beating, sensitivity of measurement can be increased by several orders of magnitude.This award is jointly supported by the Division of Electrical and Communications Systems and the Office of International Science and Engineering.