Optical and Infrared Observations of Pulsar Wind Nebulae

The extended nebulae formed as pulsar winds expand into their surroundings provide information about the composition of the winds, the injection history from the host pulsar, and the material into which the nebulae are expanding. Observations from across the electromagnetic spectrum provide constraints on the evolution of the nebulae, the density and composition of the surrounding ejecta, and the long-term fate of the energetic particles produced in these systems. Optical and infrared observations in particular reveal information that may not be observable at other wavelengths, including the presence of spectral features in the PWN particle spectrum, shocked supernova ejecta, and newly formed dust. Here we provide a summary of the growing number of optical and infrared observations of pulsar wind nebulae and what they tell us about the evolution of these systems and their host supernova remnants.