Managing spectral properties and Schmidt mode content of squeezed vacuum light using sum-frequency converter

Capabilities of quantum optical sum-frequency converter seeded by squeezed light are investigated and described analytically in the case when several frequency Schmidt modes are involved in nonlinear process. Methods to manage and manipulate extensively the properties and mode content of multimode multipartite non-classical squeezed field state are developed. Possibility to control the photon numbers in different Schmidt modes of squeezed light simultaneously is demonstrated. The significant phase sensitivity of the converter is established. Tailoring the spectral distribution of the output light due to the phase effects and variable coupling between modes in the converter is demonstrated. In the case of twin-beam seeding the effect of changing the conjugated correlated frequency mode is found which allows to manipulate the correlations between photons. The developed methods to vary the efficient number of Schmidt modes of squeezed light are strongly required for important practical applications and quantum technology.