Dual-layer volume holographic optical elements for three-wavelength optical disk pickup

A dual-layer volume holographic optical element is proposed as a beam-split ting clement for a three-wavelength (lambda = 0.4 mu m, 0.65 mu m and 0.8 m u m) optical disk pickup. We fabricated it for normal incidence using photo polymer film via an inexpensive laminate process. It is demonstrated that i t exhibited excellent wavelength selectivity (extinction ratio greater than or equal to similar to 100) with a high diffraction efficiency of 99.7%. T his element could be a key device in a next-generation multi wavelength opt ical disk pickup.