n365723SE Academic Article uri icon


  • A general theory is presented to describe optomechanical interactions of acoustic phonons, having extremely long lifetimes in superfluid He4, with optical photons in the medium placed in a suitable electromagnetic cavity. The acoustic nonlinearity in the fluid motion is included to consider processes beyond the usual linear process involving the absorption or emission of one phonon at a time. We first apply our formulation to the simplest one-phonon process involving the usual resonant anti-Stokes upconversion of an incident optical mode. However, when the allowed optical cavity modes are such that there is no single-phonon mode in the superfluid, which can give rise to a resonant allowed anti-Stokes mode, we must consider the possibility of two-phonon upconversion. For such a case, we show that the two-step two-phonon process could be dominant. We present arguments for a large two-step process and negligible single-step two-phonon contribution. The two-step process also shows interesting quantum interference among different transition pathways. 2014 American Physical Society.

published proceedings

  • Physical Review A

author list (cited authors)

  • Agarwal, G. S., & Jha, S. S.

publication date

  • January 1, 2014 11:11 AM