Completeness and Nonclassicality of Coherent States for Generalized Oscillator Algebras

Figure 2

The 50 : 50 beam splitter represented by the operator in (46). This is a two-channel optical device operating on states , where the ket at the left (right) stands for “horizontal” (“vertical”) signal. The dashed dotted arrow represents classical states like the vacuum while the continuous arrows are associated with nonclassical states like the number eigenstates .