Diffractive Optics: From Basic Research to Practical Applications

A diffractive optical element is an optical device that utilizes interference and diffraction, rather than refraction or reflection, to shape an emerging wavefront. In this talk we will concentrate on the image-forming capabilities of diffractive optics. Traditional Fresnel zone plates are characterized by low efficiency as a result of their construction with alternating clear and opaque regions and do not find wide application. Volume holography has distinct advantages for certain applications; however, environmental and material issues preclude its use in many applications. The majority of applications today utilize surface-relief diffractive optical elements. Surface-relief diffractive optics make use of precision-engineered surface structures to provide wavefront transformations in optical phase and can be highly efficient. In the past few years, diffractive optics has received overwhelming attention and numerous commercial and government applications of the technology are being developed. A key factor for this transition from the research laboratories to practical applications is the improvements in the manufacturing processes that provide high quality (high diffraction efficiency/low scatter) diffractive optical elements.