Optical and Quantum Electronics

, Volume 42, Issue 4, pp 215-229

First online:

Higher-order squeezing and sub-poissonian photon statistics in CARS and CAHRS

  • D. K. GiriAffiliated withDepartment of Physics, Sindri College, Sindri, P.O. Sindri Email author 
  • , P. S. GuptaAffiliated withDepartment of Applied Physics, Indian School of Mines
  • , M. K. MahanAffiliated withDepartment of Physics, Sindri College, Sindri, P.O. Sindri
  • , Ajay PrasadAffiliated withDepartment of Physics, PKRM College

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


The Squeezing and sub-poissonian photon statistics of an optical field are a purely quantum mechanical phenomenon and has been accepted as means of achieving noise below the quantum shot-noise limit. The effect of higher-order squeezing and sub-poissonian nature of an optical field in coherent anti-Stokes Raman scattering (CARS) and coherent anti-Stokes hyper Raman scattering (CAHRS) are investigated under short-time approximation. The coupled Heisenberg equations of motion involving real and imaginary parts of the quadrature operators are established and solved under short-time scale. The dependence of squeezing on the number of photons is also investigated. It is also shown that higher-order squeezing allows a much larger fractional noise reduction than lower-order squeezing. The occurrence of amplitude squeezing effects of the radiation field in the fundamental mode is investigated in both the processes. The present work shows that squeezing is greater in CAHRS than the corresponding squeezing in CARS. It is also shown that squeezing is greater in stimulated process than corresponding squeezing in spontaneous interaction. The conditions for obtaining maximum and minimum squeezing are obtained. The photon statistics of the pump mode in the processes has also been investigated and found to be sub-poissonian in nature.


Higher-order Squeezing of radiation Sub-poissonian photon statistics CARS CAHRS Photon-number operator