The roles of the asymmetry of coherent light and of an active medium in squeezed-state generation in a weakly noncentrosymmetric semiconductor are discussed. It is suggested that origin of medium asymmetry lies in the parity indefiniteness of the transition states, whereas field asymmetry is due to the polarization property of light. Third-order nonlinear optical susceptibility is obtained from the semiclassical density matrix approach, whereas the light-squeezing process is studied by use of Heisenberg’s equation of motion. The analysis is applied to GaAs that has been duly irradiated by a tunable nanosecond pulsed Co:MgF2 laser with its photon energy off resonant below the semiconductor’s band edge. It has been found that the effect of asymmetry on squeezed-state generation and photon number is finite only when both of the asymmetries are present simultaneously. One may also notice that the asymmetry improves the squeezing level and reduces the time span of squeezed-light generation.
© 2003 Optical Society of America
Harneet Kaur Gahir, Pratima Sen, and Pranay K. Sen, "Significance of field and medium asymmetry for the generation of squeezed light," J. Opt. Soc. Am. B 20, 871-877 (2003)