<title>High-resolution reflection holography using DuPont photopolymer holographic recording film</title>

Abstract

We report an experimental study of the use of DuPont photopolymer Holographic Recording Film (HRF) to record high resolution reflection holograms. The goals of this work are to investigate techniques for recording images of the 3D surfaces of objects, such as integrated circuit chips, without the use of imaging optics and step and repeat techniques, and to investigate techniques for reconstructing these images through a conventional or slightly modified optical microscope. We use the Denisyuk reflection geometry to record single wavelength and multiple wavelength contact-copy and near-contact holograms of an integrated circuit chip. We present photographs of the holographic reconstructions as generated and viewed through a conventional microscope. The images demonstrate color contrast and clearly resolved features of less than 1 micron. In addition, we present an experimental investigation and theoretical modeling of the grating formation process in the DuPont photopolymer HRF. Experiments are described which measure the real-time growth and accompanying real-time shrinkage of reflection gratings. A theory is outlined that includes coupling of the writing beams with the real time growth and shrinkage of nonuniform gratings throughout the thickness of the recording emulsion. Results are presented for three types of DuPont photopolymer HRF.