Journal of Modern Optics Vol. 55, No. 11, 20 June 2008, 1697–1711 Amplitude-squared and amplitude-cubed squeezing in stimulated Raman and in spontaneous Raman scattering Biswajit Sen and Swapan Mandal  Department of Physics, Visva-Bharati, Santiniketan, India (Received 6 October 2007; final version received 16 October 2007) Coherent light coupled to a third-order nonlinear medium is responsible for spontaneous and for stimulated Raman processes. The analytical solutions up to second order in coupling constants of various field modes for spontaneous Raman and for stimulated Raman processes are utilized to obtain the amplitude- squared and amplitude-cubed squeezing of the input coherent light. The amplitude-squared and amplitude-cubed squeezing are completely ruled out for all modes for spontaneous Raman processes. For stimulated Raman processes, we observe that the squeezing for amplitude-squared and amplitude-cubed are possible for pump and for vibrational phonon modes. It is found that the percentage of higher ordered amplitude squeezing decreases with the increase of the orders. The squeezing in Stokes and in anti-Stokes modes are ruled out even for stimulated Raman processes. Keywords: amplitude-squared squeezing; stimulated Raman scattering 1. Introduction Due to the discoveries of new laser sources, the field of quantum optics and the laser spectroscopy are enriched in a greater way. Interestingly, the quantum statistical properties of these new sources are quite different compared to those of the ordinary incandescent light sources. Among these nonclassical quantum statistical properties of the radiation fields, the squeezed states of the radiation fields could find potential applications in gravitational wave detection and in communication systems [1,2]. The observation of a squeezed state was first made by Slusher et al. in the nondegenerate four wave mixing due to a Na atom [3]. Of course, since that time, a large number of laboratories have reported the squeezing phenomena in various nonlinear optical processes. Squeezing in the normal sense employs second-order moments of the field operators. However, it is natural to explore the squeezing of higher orders which employ higher order moments of the field operators. The idea of higher order *Corresponding author. Email: swapanvb@rediffmail.com ISSN 0950–0340 print/ISSN 1362–3044 online # 2008 Taylor & Francis DOI: 10.1080/09500340701765782 http://www.informaworld.com