  Nonlinear quantum photonics serves as a cornerstone in photonic quantum
technologies, such as universal quantum computing and quantum communications.
The emergence of integrated photonics platform not only offers the advantage of
large-scale manufacturing but also provides a variety of engineering methods.
Given the complexity of integrated photonics engineering, a comprehensive
simulation framework is essential to fully harness the potential of the
platform. In this context, we introduce a nonlinear quantum photonics
simulation framework which can accurately model a variety of features such as
adiabatic waveguide, material anisotropy, linear optics components, photon
losses, and detectors. Furthermore, utilizing the framework, we have developed
a device scheme, chip-scale temporal walk-off compensation, that is useful for
various quantum information processing tasks. Applying the simulation
framework, we show that the proposed device scheme can enhance the squeezing
parameter of photon-pair sources and the conversion efficiency of quantum
frequency converters without relying on higher pump power.
