  We propose a hybrid silicon waveguide scheme to avoid the impact of noise
photons induced by pump lights in application scenarios of quantum photonic
circuits with quantum light sources. The scheme is composed of strip waveguide
and shallow-ridge waveguide structures. It utilizes the difference of biphoton
spectra generated by spontaneous four wave mixing (SFWM) in these two
waveguides. By proper pumping setting and signal/idler wavelength selection,
the generation of desired photon pairs is confined in the strip waveguide. The
impact of noise photons generated by SFWM in the shallow-ridge waveguide could
be avoided. Hence, the shallow-ridge waveguide could be used to realize various
linear operation devices for pump light and quantum state manipulations. The
feasibility of this scheme is verified by theoretical analysis and primary
experiment. Two applications are proposed and analyzed, showing its great
potential on silicon-based quantum photonic circuits.
