Abstract: Detection of individual objects using a light source and a whispering gallery mode (WGM) resonator. Light from the whispering gallery mode (WGM) resonator is analyzed. The presence of an object is determined based on mode splitting associated with the light received by the photodetector. For example, the presence of the object may be determined based on the distance between two whispering gallery modes and/or the linewidths of the two modes in a transmission spectrum. Alternatively, the presence of the object may be determined based on a beat frequency that is determined based on a heterodyne beat signal produced by combining split laser modes in the received light from a WGM microcavity laser.

Abstract: A particle detection system is provided. The particle detection system includes at least one tapered optical fiber, a light source configured to transmit light through the at least one tapered optical fiber, a photodetector configured to measure a characteristic of the light being transmitted through the at least one optical fiber, and a computing device coupled to the photodetector and configured to determine whether a nanoparticle is present within an evanescent field of the at least one tapered optical fiber based on the measured light characteristic.

Abstract: Detection of individual objects using a light source and a whispering gallery mode (WGM) resonator. Light from the whispering gallery mode (WGM) resonator is analyzed. The presence of an object is determined based on mode splitting associated with the light received by the photodetector. For example, the presence of the object may be determined based on the distance between two whispering gallery modes and/or the linewidths of the two modes in a transmission spectrum. Alternatively, the presence of the object may be determined based on a beat frequency that is determined based on a heterodyne beat signal produced by combining split laser modes in the received light from a WGM microcavity laser.