Holography and coherent imaging

Fall 2009

Homework 4

Due 25 September 2009

  1. A certain holographic material has a maximum change in refractive index of 0.00001. A hologram is recorded to saturation in the material. The signal beam is incident at 20 degrees to the surface normal and the reference beam is 20 degrees on the opposite side of the surface normal. The recording wavelength is 532 nm. Use coupled mode theory to plot
    1. The diffraction efficiency as a function of hologram thickness for Bragg matched reconstruction.
    2. The maximum diffraction efficiency for any thickness as a function of incidence angle for the reconstruction wave.
    3. The maximum diffraction efficiency as a function of reconstruction beam wavelength when the reconstruction beam is incident at the 532 nm Bragg angle.
    4. The Bragg match angle as a function of wavelength.
  2. Write a 1 page essay discussing the information capacity of volume holographic data storage. What factors determine the information capacity? Is wavelength or angular multiplexing preferred? What alternative materials or design strategies might be applied?