Nonclassicality in off-resonant Raman process

Highlights: • Role of frequency detuning parameter in off-resonant Raman process is studied. • Nonclassicality can be induced/enhanced due to non-zero value of detuning parameter. • Detuning in Stokes process enhances (decreases) pump-phonon (Stokes-phonon) pair generation. • Nonclassicality revealed by joint intensity quasidistribution can be controlled by detuning parameter. -- Abstract: The detuning parameter in experimentally feasible off-resonant Raman process is shown as a control parameter to probe and enhance the nonclassicality generated in the output of the process. Specifically, the normal characteristic function is obtained for the process as a function of detuning parameters in Stokes and anti-Stokes generation processes using more general solution than the conventional short-time solution under complete quantum treatment, which remains in the multimode Gaussian form. Single- and two-mode squeezing and antibunching as well as intermodal entanglement are reported in terms of experimentally accessible quantum noise fluctuations considering either phonon mode coherent or chaotic. Further, the joint photon-phonon number and integrated intensity distributions reveal a higher number of Stokes-phonon (pump-phonon) pair generation for the lower (higher) values of detuning parameter in Stokes generation. Pump-phonon pair generation is also supported by the lower values of detuning parameter in anti-Stokes generation.