Selective Properties of Controlled Reflective Holograms Recorded in a Polymer - Liquid Crystal Composite

The selective properties of reflective holograms recorded in a polymer-liquid crystal composite, controlled by mechanical stretching or compression of the hologram have been studied. Based on the theory of diffraction by Kogelnik, an analysis of the effect of mechanical tension and compression of a phase reflective holographic grating across its thickness on the spectral characteristics of the grating is made. A comparative analysis of experimental data and simulation results is carried out. It is shown that when the hologram is mechanically compressed, the wavelength corresponding to the maximum in the reflection spectrum is shifted to the short-wavelength region of the spectrum, and when it is stretched – to the long-wavelength region. The wavelengths of the maximum in the reflection spectrum for the theoretical and experimental dependences corresponding to the same magnitude of compression or tension are proximate. An example of instrumental device using these guided holograms is presented.