Paper 2.11: N. Bloembergen, “Conservation of angular momentum for optical processes in crystals,” in Polarisation, Matière et Rayonnement, edited by Claude Cohen-Tannoudji, Presses Universitaires, Paris 1969, pp. 109–119.
Reprinted with permission of Presses Universitaires, Paris.
The question of conservation of angular momentum in nonlinear optics had intrigued me in connection with the selection rules of harmonic generation by circularly polarized light in media with various types of axial symmetry. We had conducted a systematic experimental investigation of this problem in a single crystal of NaClO3 with 23 cubic symmetry, which was reported in “Second-harmonic light generation in crystals with natural optical activity” (H.J. Simon and N. Bloembergen, Phys. Rev. 171, 1104–1114, 1968).
It was natural to write a more general review of angular momentum conservation in optical processes for a volume in honor of Nobel laureate Alfred Kastler who had introduced the method of optical angular momentum pumping. Professor Kastler wrote me a nice thank-you note saying that he had enjoyed reading my contribution which had provided him with some additional insight. The paper is reprinted in this volume to make such insights available to other members of the quantum electronics community.
