Optically switched volume holographic elements

We optically switched the diffraction efficiency of volume holographic elements recorded in DMP-128 photopolymer by use of a thermal nonlinearity of the liquid crystal 5CB. The liquid crystal was incorporated into the volume grating. The diffraction efficiency of small areas of the grating was switched with a control beam power of several milliwatts. The intensity of a signal beam at a different wavelength and arbitrary power was switched with time constants below 1 ms.