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.Comment: 9 pages, 7 figure