Reversal of Photoinduced Bending of Crystals Due to Internal Refraction of Light

The well-known effect of bending acicular crystals undergoing photochemical reactions is associated with the transformation gradient across crystal thickness caused by absorption light. It believed that direction unambiguously dictated sign axial component reaction strain and due to higher light intensity on irradiated side crystal. In this study, it shown experimentally theoretically thin a convex surface bend in opposite if their less than penetration depth. reversal lens effect, able overcome provide rear A [Co(NO3)5NO2]Cl(NO3) experiencing nitro-nitrito photoisomerization, begins after thinned etching 2 µm when at wavelengths 523 nm, 465 403 absorbed depth more 10 crystal, but bends normal under 350 nm about 1 µm. experimental results are fully confirmed modeling interaction plane EM wave various cross sections.