Infinitesimal Multimode Bargmann-State Representation*

In the Hilbert space of a light mode (harmonic oscillator), we construct a representation, in which an arbitrary state vector is expanded using Bargmann states ‖α〉 with real parameters α being in an infinitesimal vicinity of zero. The complete Hilbert-space structure is represented in the one- and multimode cases as well, making the representation able to deal with problems of continuous-variable quantum information processing.