Dual-Layer Volume Holographic Optical Elements for Three-Wavelength Optical Disk Pickup

Abstract

A dual-layer volume holographic optical element is proposed as a beam-splitting element for a three-wavelength (λ=0.4 µm, 0.65 µm and 0.8 µm) optical disk pickup. We fabricated it for normal incidence using photopolymer film via an inexpensive laminate process. It is demonstrated that it exhibited excellent wavelength selectivity (extinction ratio ≥∼100) with a high diffraction efficiency of 99.7%. This element could be a key device in a next-generation multi wavelength optical disk pickup.