Highly-precision sizing a single metal nanoparticle using a microcavity

Precision measurement plays a very important role in many field including optics, astronomy, biochemistry, atmospheric science, environmental engineering, dusty plasma, etc. Here, we propose an efficient scheme to investigate the relationship between linewidth and radius of the metal nanoparticle (MNP) in a hybrid optical microcavity system that included a quantum emitters interacting with a MNP. By using detailed numerical simulations and analytical modeling, we find that the linewidth of the amplification window is sensitive to the radius of MNP. Subsequently, we discuss the application of such a hybrid optical microcavity system as a family of high-sensitivity sensor for measuring the tiny radius of the MNP. Using experimentally achievable parameters, we identify the detection sensitivity of the sensor can arrive at approximately 2.6 GHz nm−1. The present investigation provides a route toward guiding the design of sensitive devices.