Washington University

Da-Ren Chen

Lan Yang

Sahin Kaya Ozdemir

Jiangang Zhu

Chaolong Qi

Lina He

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.

Nanoscale object detection using a whispering gallery mode resonator

An apparatus for measuring particle size distribution includes a charging device and a precipitator. The charging device includes a corona that generates charged ions in response to a first applied voltage, and a charger body that generates a low energy electrical field in response to a second applied voltage in order to channel the charged ions out of the charging device. The corona tip and the charger body are arranged relative to each other to direct a flow of particles through the low energy electrical field in a direction parallel to a direction in which the charged ions are channeled out of the charging device. The precipitator receives the plurality of particles from the charging device, and includes a disk having a top surface and an opposite bottom surface, wherein a predetermined voltage is applied to the top surface and the bottom surface to precipitate the plurality of particles.

Growing community of inventors

St. Louis, MO, United States of America

Da-Ren Chen