A Theoretical and Experimental Investigation of Linear and Nonlinear Focussing Chirped Optical Diffraction Gratings
Abstract
In the past the focussing properties of chirped grating structures have been investigated in various disciplines including optics, acousto-optics and acoustics. In this paper we present the results of a detailed theoretical and experimental study of one such structure, namely the chirped optical diffraction grating, although many of the conclusions are of more general validity. We derive some useful fundamental properties of such focussing gratings, and show that to first order their behaviour is similar to that of various other classical components such as focussing lenses, grating spectrometers, and matched filters for chirped waveforms. However we also describe a fascinating range of second-order differences in behaviour, for example concerning the physical locations of the multiple foci, and the sidelobe structures within and perpendicular to the focal plane. For devices of large numerical aperture we demonstrate the advantages of using a non-linear chirp grating structure, e.g. for sidelobe suppression in the focal plane, and point out that surface acoustic wave (SAW) techniques can be used to generate the non- linear chirp waveforms necessary to implement such gratings in acousto-optic devices. Great Britain.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1988
- Accession Number
- ADA203396
Entities
People
- C. L. West
- M. F. Lewis
Organizations
- Royal Signals and Radar Establishment