Squeezing enhanced nonlinearity sensing in dissipatively coupled optical systems

Abstract

In this manuscript, we propose a proposal to enhance the sensitivity of two cavities to its intrinsic nonlinearities by pumping one of the cavities. The system consists of two dissipatively coupled micro-ring cavities, one of which is driven by a squeezed laser. With a low pump rate, the spectrum of the system acquires a real spectral singularity. We find that this singularity is very sensitive to the pumping and nonlinearity of the system, and compared to the case of coherent drive, the sensitivity of the system to intrinsic nonlinearities at the singularity can be further increased by using the squeezed laser. Moreover, the scheme is robust gainst fabrication imperfections. This work would open a new avenue for quantum sensors, which could find applications in many fields, such as the precise measurement and quantum metrology.