The influence of diffractive optics on modern optical engineering has been considerable. The paper discusses a wide variety of applications of diffractive surfaces in the infrared and visible wavebands. Successful developments in low mass and multi-waveband infrared optics are described and results presented from manufactured hardware. The use in the visible waveband for real-time 3-D imagery, high power magnification of full colour displays, and possible use in diffractive-only helmet displays are examined for their potential. The limitation in the use of conventional diffractive surfaces for wide spectral bandwidth applications is described along with a method for alleviating this problem.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.