The field of physical optics studies not the particle nature but this nature of light
The field of quantum optics involves the study of this particle ... Of 
course, this is just one way of dividing up the various studies of... [DOC] [TLE] The Nature of Light [PAR] Photons are different from particles of matter in that they have no mass and 
always move at ... To understand the nature of light and how it is normally created
, it is ... their work in the September 1, 1997, issue of the journal Physical Review 
Letters.