The authors provide a sound and wide coverage on the theoretical foundations of PCFs and the different numerical models that are in use for the design of these fibres. -- From the foreword by Professor Fetah Benabid CNRS, Xlim Research Institut, Universit de Limoges As befits a book on such an interdisciplinary topic it covers necessary basic information, but also has considerable breadth stretching to cover experimental topics, numerics, sophisticated mathematics and interweaves into all of this the beauty of the underlying physics. -- From the foreword by Professor Richard Craster Professor of Applied Mathematics, Imperial College London