Abstract
We give an overview of the properties and uses for spin waves.  Their frequencies typically are in the 100 MHz to 2 THz range.They interact strongly with electromagnetic waves and this can lead to very unusual effects.
For example reflection of microwaves (or infrared radiation) from magnetic materials can be nonreciprocal.
This means the reflection in one direction can be large (80%) but just reversing the direction of the input and reflected waves can lead to a very small reflection (10%). This is like creating a diode like behavior for microwaves. We also discuss the surprising effect where spin waves can be focused and avoid the diffraction limit.
Unlike normal lenses, the focusing direction can be changed by an applied magnetic field.

Biographical Information
Bob Camley is a Professor of Physics at the University of Colorado at Colorado Springs.  Professor Camley is also the Director of the Center for Magnetism and Magnetic Nanostructures and the Director of the Biofrontiers Center at Colorado Springs.  He obtained his PhD in 1979 from the University of California at Irvine.  He then worked at the Max Planck Institute in Stuttgart, Germany, for two years as a post-doctoral researcher.  In 1982 he became a faculty member at the University of Colorado.  He is the author of more than 200 papers.  One of these was the first theoretical explanation (with J. Barnas) of giant magnetoresistance.   (The experimental discovery of giant magnetoresistance by Fert and Gruenberg won a Nobel Prize in 2007.)   In addition to his research, Professor Camley has won many teaching awards.