Research in Fang group focuses on study of light-matter interactions and light manipulation at micro- and nano-scales. Guided by exploratory theories, research emphasis is given to device demonstrations and multi-scale integrations for applications in photonic quantum information processing and quantum metrology. Current research projects include:

  • Quantum photonics

Photonic integrated circuits (PICs) with strong nonlinearity are an emerging platform for quantum information processing. We are exploring materials with substantial bulk nonlinearity and developing PICs to enable key resources and protocols for photonic quantum information processing.


  • Optomechanics

Control of phonons–quanta of vibrations–in engineered structures using radiation-pressure force represents an emerging quantum technique for sensing and information transduction. We are developing a new breed of chipscale optomechanical architecture based on mechanical bound states in the continuum to enable new sensing modalities and macroscopic quantum phenomena.


  • Quantum metrology

Quantum metrology is one of the major applications of quantum information science. Along with theoretical explorations, we create nonclassical photonic and phononic states enabled by our chipscale architectures for quantum sensing beyond the standard quantum limit.


Highlighted publications:

H. Tong, S. Liu, M. Zhao, and K. Fang, “Observation of phonon trapping in the continuum with topological charges”, Nature Communications 11, 5216 (2020). Link

K. Fang, J. Luo, A. Metelmann, M. H. Matheny, F. Marquardt, A. A. Clerk, and O. Painter, “Generalized nonreciprocity in an optomechanical circuit via synthetic magnetism and reservoir engineering”,  Nature Physics 13, 465–471 (2017). Link

K. Fang, M. H. Matheny, X. Luan, and O. Painter, “Optical transduction and routing of microwave phonons in cavity-optomechanical circuits”, Nature Photonics 10, 489 (2016). Link

K. Fang, Z. Yu, and S. Fan, “Realizing effective magnetic field for photons by controlling the phase of dynamic modulation”, Nature Photonics 6 782-787 (2012). Link

K. Fang, V. M. Acosta, C. Santori, Z. Huang, K. M. Itoh, H. Watanabi, S. Shikata, and R. G. Beausoleil, “High-sensitivity magnetometry based on quantum beats in diamond nitrogen-vacancy centers”, Physical Review Letters 110, 130802 (2013). Link