Abstract
The paper is a survey of properties and applications of optical elements which are volume Bragg gratings
(VBGs) recorded in photo-thermo-refractive (PTR) glass. These elements are narrow band filters that
operate in spectral, angular and temporal domains. They provide spectral narrowing, stabilization and
tuning of laser radiation; narrowing of divergence and beam steering; stretching, compression and temporal
shaping of laser pulses, integration of different laser components in the same material and fabrication
of monolithic solid state lasers; and passive and active coherent combining along with high density
spectral combining of fiber lasers.
