Linear quantum feedback networks with squeezing components

The aim of this paper is to extend linear quantum dynamical network theory to include static Bogoliubov components (such as squeezers). Within this integrated quantum network theory we provide general methods for cascade or series connections, as well as feedback interconnections using linear fractional transformations. In addition, we define input-output maps and transfer functions in this quantum context, show how they can be useful. We also discuss the underlying group structure in this theory arising from series interconnection.