SU(2)- and SU(1,1)-squeezing of interacting radiation modes
  In this communication we discuss SU(1,1)- and SU(2)-squeezing of an interacting system of radiation modes in a quadratic medium in the framework of Lie algebra. We show that regardless of which state being initially considered, squeezing can be periodically generated. 
M. Sebawe Abdalla, Faisal A. A. El-Orany and J. Perina
quant-ph