We report the method of accurate diffraction efficiency control for multiplexed volume holographic gratings in dry photopolymer films (DuPont HRF-600). Based on the experimental evaluations of the grating formation characteristics in dry photopolymer films, we present the way to develop the practical recording schedules for the fabrication of holographic gratings under accurate diffraction efficiency control. Using this method, we obtained single holographic gratings with the desired diffraction efficiency (variation 2.5%) and high-efficiency equal-strength (47%/47%) double holographic gratings. As a practical application, we demonstrated the centralized optical backplane architecture with uniform fan-outs using the single and equal-strength double holographic gratings we recorded. © 2002 Society of Photo-Optical Instrumentation Engineers.