Light-matter interaction, including the transmission, reflection, and absorption of light, is a fundamental principle of optical and photonic devices. For example, material characterization, biomedical imaging, molecular manipulation, and non-classical light generation are all indispensable for interacting light with matter. However, such intriguing applications often require enormous optical intensities to be realized. Thanks to optical microresonators with high quality (Q) factors and small mode volumes (V), an intense intra-cavity power can be reached through temporal accumulation and spatial confinement of light. The light-matter interaction is greatly enhanced in a small-footprint resonator with moderate input optical power, such as whispering-gallery-mode (WGM) microcavities. Particularly, the outstanding enhancement has found high-Q micro-resonators as a promising ultrahigh-sensitivity sensing platform.

In this dissertation proposal, I will discuss the challenges of current optical sensors and introduce several demonstrations of versatile photonic systems with further enhanced light-matter interactions. The first project is to create and implement a novel scanning microprobe with WGM-nanoplasmonics hybrid enhancement. The “fingerprint” of analytes is acquired by probing Raman scattering of target molecules, and 2D Raman imaging is demonstrated by scanning the sample surface. The second project is to extend the exceptional-point (EP)-enhanced sensitivity to general optical sensors. EP enhancement can be endowed to any sensor by connecting and tuning it with our EP control unit. Finally, in the third project, I aim at chip-scale integration of multiple functional materials and optical components. The in-house fabrication processes of silicon, polymer, and lithium niobate photonic chips have been developed. I will discuss their potential in all-optical controlling, sensing and measurement, and non-classical light generation.

Light-matter interaction, including the transmission, reflection, and absorption of light, is a fundamental principle of optical and photonic devices. For example, material characterization, biomedical imaging, molecular manipulation, and non-classical light generation are all indispensable for interacting light with matter. However, such intriguing applications often require enormous optical intensities to be realized. Thanks to optical microresonators with high quality (Q) factors and small mode volumes (V), an intense intra-cavity power can be reached through temporal accumulation and spatial confinement of light. The light-matter interaction is greatly enhanced in a small-footprint resonator with moderate input optical power, such as whispering-gallery-mode (WGM) microcavities. Particularly, the outstanding enhancement has found high-Q micro-resonators as a promising ultrahigh-sensitivity sensing platform.

In this dissertation proposal, I will discuss the challenges of current optical sensors and introduce several demonstrations of versatile photonic systems with further enhanced light-matter interactions. The first project is to create and implement a novel scanning microprobe with WGM-nanoplasmonics hybrid enhancement. The “fingerprint” of analytes is acquired by probing Raman scattering of target molecules, and 2D Raman imaging is demonstrated by scanning the sample surface. The second project is to extend the exceptional-point (EP)-enhanced sensitivity to general optical sensors. EP enhancement can be endowed to any sensor by connecting and tuning it with our EP control unit. Finally, in the third project, I aim at chip-scale integration of multiple functional materials and optical components. The in-house fabrication processes of silicon, polymer, and lithium niobate photonic chips have been developed. I will discuss their potential in all-optical controlling, sensing and measurement, and non-classical light generation.