Book contents
- Frontmatter
- Contents
- Preface
- Preface to the first edition
- 1 Introduction
- 2 Wavefront reconstruction
- 3 The reconstructed image
- 4 Types of holograms
- 5 Optical systems and light sources
- 6 The recording medium
- 7 Practical recording materials
- 8 Holograms for displays
- 9 Colour holography
- 10 Computer-generated holograms
- 11 Special techniques
- 12 Applications in imaging
- 13 Holographic optical elements
- 14 Information storage and processing
- 15 Holographic interferometry
- 16 Holographic interferometry: Further applications
- 17 Holographic interferometry: Advanced techniques
- 1 Interference and coherence
- 2 The Fourier transform, convolution, and correlation
- 3 Wave propagation and diffraction
- 4 Speckle
- 5 The H & D curve
- Bibliography
- References
- Author index
- Subject index
13 - Holographic optical elements
Published online by Cambridge University Press: 05 June 2012
- Frontmatter
- Contents
- Preface
- Preface to the first edition
- 1 Introduction
- 2 Wavefront reconstruction
- 3 The reconstructed image
- 4 Types of holograms
- 5 Optical systems and light sources
- 6 The recording medium
- 7 Practical recording materials
- 8 Holograms for displays
- 9 Colour holography
- 10 Computer-generated holograms
- 11 Special techniques
- 12 Applications in imaging
- 13 Holographic optical elements
- 14 Information storage and processing
- 15 Holographic interferometry
- 16 Holographic interferometry: Further applications
- 17 Holographic interferometry: Advanced techniques
- 1 Interference and coherence
- 2 The Fourier transform, convolution, and correlation
- 3 Wave propagation and diffraction
- 4 Speckle
- 5 The H & D curve
- Bibliography
- References
- Author index
- Subject index
Summary
Holographic diffraction gratings
Diffraction gratings formed by recording an interference pattern in a suitable light-sensitive medium (commonly called holographic diffraction gratings) have replaced conventional ruled gratings for many applications. While Burch and Palmer [1961] first showed that transmission gratings could be made by photographing interference fringes using silver halide emulsions, it was the use of photoresist layers coated on optically worked blanks which finally led to the production of spectrographic gratings of high quality [Rudolph & Schmahl, 1967; Labeyrie & Flamand, 1969]. After processing, the photoresist layer yields a relief image (see section 7.3) which can be coated with an evaporated metal layer and used as a reflection grating.
Holographic gratings have several advantages over ruled gratings. Besides being cheaper and simpler to produce, they are free from periodic and random errors and exhibit much less scattered light. In addition, it is possible to produce much larger gratings of finer pitch, as well as gratings on substrates of varying shapes, and gratings with curved grooves and varying pitch. This makes it possible to produce gratings with unique focusing properties and opens up the possibility of new designs of spectrometers [Namioka, Seya & Noda, 1976].
Against this, their main disadvantage is that the groove profile cannot be controlled as easily as in ruled gratings. While even a sinusoidal profile can give high diffraction efficiencies for small grating spacings (≈ λ) [Loewen, Maystre, McPhedran & Wilson, 1975], it is usually necessary to produce a triangular groove profile for maximum diffraction efficiency.
- Type
- Chapter
- Information
- Optical HolographyPrinciples, Techniques and Applications, pp. 213 - 224Publisher: Cambridge University PressPrint publication year: 1996