Twisted Electromagnetic Multi-Gaussian Schell-Model Pulsed Source and Its Propagation

Here, a novel family of random electromagnetic sources (twisted electromagnetic multi-Gaussian Schell-model pulsed beams) exhibiting transverse orbital angular momentum is proposed. The physically realizable conditions for these sources are established, and the analytical formulas of the cross-spectral density matrix elements of the beam propagating through an ABCD optical system are derived within the framework of the extended Collins formula. The behaviors of the spectral density, and the spectral degree of coherence of the beam during transmission are investigated numerically. This work enriches the classical theory of stochastic electromagnetic beams propagation, and may benefit applications requiring a specified degree of beam coherence with transverse orbital angular momentum.