Diffraction properties of stratified volume holographic optical elements

Abstract

We present a unified treatment of the diffraction properties of stratified volume holographic optical elements (SVHOE's). We show that the relative phasing of the diffraction orders as they propagate from layer to layer gives rise to a unique notched diffraction response of the +1 order (for the case of Bragg incidence) as a function of the normalized buffer-layer thickness, the grating spatial frequency, and the readout wavelength. For certain combinations of these parameters Bragg diffraction behavior characteristic of volume holographic optical elements (VHOE's) is observed, whereas for other combinations pure Raman-Nath behavior periodically recurs. By using these same relative-phasing arguments, the principal features of the periodic angular sensitivity of the +1 and-1 orders can be predicted. In addition to examining the fundamental aspects of SVHOE diffraction behavior, we discuss several possible applications, including optical array generation, spatial frequency filtering, and wavelength notch filtering. With the use of the SVHOE concept, holographic materials with otherwise exemplary characteristics that are currently available only in thin-film form can be used in structures designed either to access unique SVHOE diffraction properties or to emulate conventional VHOE's.

Properties of multilayer nonuniform holographic structures

“…Nordin [2] considered the structures consisting of thin gratings separated by intermediate layers, presented an analytical model for calculating their diffraction efficiency, and discussed a possible employment of these gratings as spectral filters. In [3,4], similar structures are called SVHOE (Stratified Volume Holographic Optical Elements).…”

Anisotropic diffraction of stratified volume holographic grating in photorefractive media

“…They have many important applications in optical information processing and computing. Many novel devices can be made, such as optical array generation [1][2][3][4], wavelength notch filtering, grating spatial frequency filtering [3,4], and beam-scanning elements [5].…”

“…A SVHOE consists of multiple layers of thin photosensitive holographic recording layer interleaved with optically passive buffer layers. The diffraction properties of SVHOEs have been studied in detail by using the optical beam propagation method [3]. Since not all thin-film photosensitive materials can be thin enough to yield strictly Raman-Nath diffraction behavior within each modulation layer under all possible conditions, Yakimovich [6] studied the diffraction behavior of multiply grating which modulation layers individually exhibit Bragg diffraction behavior.…”

“…Since not all thin-film photosensitive materials can be thin enough to yield strictly Raman-Nath diffraction behavior within each modulation layer under all possible conditions, Yakimovich [6] studied the diffraction behavior of multiply grating which modulation layers individually exhibit Bragg diffraction behavior. In addition, different materials have been used in the fabrication of SVHOEs, such as photopolymers [3], dichromated gelatin films [7], and photoresist [1,8]. Comparing with these materials used in the fabrication of SVHOEs, photorefractive crystals are the most promising holographic data storage materials for their large storage density and reversibility.…”

Phase-matched gratings for enhanced forward degenerate four-wave mixing

“…Such a structure is predicted to exhibit unique diffraction properties as well as those obtained from standard volume holograms. [5][6][7] Here we assess the possibility of using phase-matched gratings to amplify the second-order diffracted beams obtained by nonlinear multiwave mixing. First we explain the concept, using expressions derived from the coupledwave theory (CWT) of permanent gratings.…”