Optical micromanipulation offers a unique insight into light-matter interaction at the mesoscopic level within the classical framework. The optical forces used in this process originate from the conservation of energy and momentum during an optical interaction. They can be determined through the use of the electromagnetic energy-momentum tensor which describes the flux of momentum and energy. However, can we use this direct opto-mechanical interaction to further our understanding of the classical nature of photons? In this paper, I generalize the momentum energy tensor and determine its eigenmodes for a given scattering object. These eigenmodes decompose the classical electromagnetic field into modes that have formally similar properties to those associated with photons i.e. modes with uniquely defined energy, momentum and polarization. This classical interpretation of photons is put forward and discussed in the context of small scattering particles. When a single photon is scattered from an object, transferring its momentum, is its final state one of the momentum energy eigenmodes? Potential experiments are discussed that could confirm this assumption in the case of single photon optical trapping and verify the "classical" nature of the photon.

Date Published: 10 September 2009
PDF: 7 pages
Proc. SPIE 7421, The Nature of Light: What are Photons? III, 74210Q (10 September 2009); doi: 10.1117/12.826152

Published in SPIE Proceedings Vol. 7421:
The Nature of Light: What are Photons? III
Chandrasekhar Roychoudhuri; Al F. Kracklauer; Andrei Yu. Khrennikov, Editor(s)