1Univ. Dept. of Physics, Vinoba Bhave University, Hazaribag
2Retd. Professor, P.G Dept. of Physics, Ranchi University, Ranchi
Online published on 4 May, 2019.
Non-linear optical properties in recent times has attracted a number of research workers as it developed new techniques novel methods to provide information's about electronic properties of atoms/molecules. New semiconducting properties are being explored. One of the observed non-linear processes of matter in interaction with radiation is two-photon absorption process. The superposition principle in quantum mechanics admits of a rotation of the Hilbert space for the system. Making use of this fact a geometrical representation of the schrodinger equation for two photon absorption process is by treating the Hamiltonian and the Density matrix of the system as vectors in aspace spanned by angular momentum matrices for J=1 as basis vectors. This description specializes the general three level problem into a problem of equi spaced levels with proper matrix elements between the two pairs of levels
Two-photon absorption, superposition principle, rotation of Hilbert space, density matrix, angular momentum as basis vectors
